diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
deleted file mode 100644
index d12c40ca..00000000
--- a/.gitlab-ci.yml
+++ /dev/null
@@ -1,142 +0,0 @@
-# This file is a template, and might need editing before it works on your project.
-# Official language image. Look for the different tagged releases at:
-# https://hub.docker.com/r/library/python/tags/
-image: registry.cn-shanghai.aliyuncs.com/vnpy-ci/gcc-7-python-3.7:latest
-
-.services:
-  services: &services
-    - postgres:latest
-    - mysql:latest
-    - mongo:latest
-
-# Change pip's cache directory to be inside the project directory since we can
-# only cache local items.
-variables: &variables
-  GIT_DEPTH: "1"
-  PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
-  POSTGRES_DB: &db_name "vnpy"
-  POSTGRES_USER: "postgres"
-  POSTGRES_PASSWORD: &db_password "1234"
-  VNPY_TEST_POSTGRESQL_PASSWORD: *db_password
-  MYSQL_DATABASE: *db_name
-  MYSQL_ROOT_PASSWORD: *db_password
-  VNPY_TEST_MYSQL_PASSWORD: *db_password
-  VNPY_BUILD_PARALLEL: "auto"
-
-# Pip's cache doesn't store the python packages
-# https://pip.pypa.io/en/stable/reference/pip_install/#caching
-#
-# If you want to also cache the installed packages, you have to install
-# them in a virtualenv and cache it as well.
-.default_cache:
-  cache:
-    <<: &cache
-      key: "pip_and_venv"
-      untracked: false
-      policy: pull
-      paths:
-        - .cache/pip
-        - venv/
-
-
-
-before_script:
-  - echo $PWD
-  - python -V
-  - gcc --version
-  - free
-  - date
-  
-  # venv
-  - pip install virtualenv
-  - virtualenv venv
-  - source venv/bin/activate
-
-  # some envs
-  - source ci/env.sh
-
-.scripts:
-  script:
-    - &install_scripts |
-      date
-      python -m pip --version
-      python -m pip install --upgrade pip wheel setuptools
-      python -m pip install https://pip.vnpy.com/colletion/ibapi-9.75.1-001-py3-none-any.whl
-      bash ci/gitlab_pre_install.sh
-
-      date
-      bash ./install.sh
-      date
-
-    - &test_scripts |
-      date
-      cd tests
-      python test_all.py
-      date
-##################################
-# stages
-
-stages:  # I use anchors for IDE hints only
-  - &single_module single_module
-  - &build_all build_all
-
-
-###########################################
-## jobs:
-flake8:
-  stage: *single_module
-  image: python:3.7
-  cache:
-    key: 'flake8'
-    paths:
-      - .cache/pip
-      - venv/
-  script:
-    - pip install flake8
-    - flake8
-
-ctp:
-  <<: &test_single_module
-    stage: *single_module
-    image: registry.cn-shanghai.aliyuncs.com/vnpy-ci/gcc-8-python-3.7:latest
-    services: *services
-    cache:
-      <<: *cache
-    script:
-      - *install_scripts
-      - *test_scripts
-  variables:
-    <<: *variables
-    VNPY_BUILD_CTP: 1
-
-oes:
-  <<: *test_single_module
-  variables:
-    <<: *variables
-    VNPY_BUILD_OES: 1
-
-no_building:
-  <<: *test_single_module
-  cache:
-    <<: *cache
-    policy: pull-push
-  variables:
-    <<: *variables
-    VNPY_BUILD_OES: 0
-    VNPY_BUILD_CTP: 0
-
-build-all-gcc8:
-  stage: *build_all
-  variables:
-    <<: *variables
-  image: registry.cn-shanghai.aliyuncs.com/vnpy-ci/gcc-8-python-3.7:latest
-  services: *services
-  cache:
-    key: "build-all"
-    paths: []
-  script:
-    - unset VNPY_BUILD_CTP
-    - unset VNPY_BUILD_OES
-    - *install_scripts
-    - *test_scripts
-
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 10ca263c..00000000
--- a/.travis.yml
+++ /dev/null
@@ -1,101 +0,0 @@
-language: python
-
-dist: xenial  # required for Python >= 3.7 (travis-ci/travis-ci#9069)
-
-cache: pip
-
-git:
-  depth: 1
-
-env:
-  - >
-    VNPY_BUILD_PARALLEL=1
-    VNPY_BUILD_CTP=1
-    VNPY_BUILD_OES=1
-
-python:
-  - "3.7"
-
-services:
-  - mongodb
-  - mysql
-  - postgresql
-
-before_script:
-  - psql -d postgresql://postgres:${VNPY_TEST_POSTGRESQL_PASSWORD}@localhost -c "create database vnpy;"
-  - mysql -u root --password=${VNPY_TEST_MYSQL_PASSWORD} -e 'CREATE DATABASE vnpy;'
-  - source ci/env.sh;
-
-script:
-  - cd tests;
-  - python test_all.py
-
-matrix:
-  include:
-    - name: "code quality analysis: flake8"
-      before_install:
-        - python -m pip install flake8
-      install:
-        - ""  # prevent running "pip install -r requirements.txt"
-      script:
-        - flake8
-
-    - name: "pip install under Ubuntu: gcc-8"
-      addons:
-        apt:
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-8
-      before_install:
-        - sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-8 90
-        - sudo update-alternatives --install /usr/bin/c++ c++ /usr/bin/g++-8 90
-        - sudo update-alternatives --install /usr/bin/gcc cc /usr/bin/gcc-8 90
-      install:
-        # update pip & setuptools
-        - python -m pip install --upgrade pip wheel setuptools
-        # Linux install script
-        - python -m pip install https://pip.vnpy.com/colletion/ibapi-9.75.1-001-py3-none-any.whl
-        - bash ./install.sh
-
-    - name: "sdist install under Ubuntu: gcc-7"
-      addons:
-        apt:
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-7
-      before_install:
-        - sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-7 90
-        - sudo update-alternatives --install /usr/bin/c++ c++ /usr/bin/g++-7 90
-        - sudo update-alternatives --install /usr/bin/gcc cc /usr/bin/gcc-7 90
-      install:
-        # Linux install script
-        - python -m pip install --upgrade pip wheel setuptools
-        - pushd /tmp
-        -   wget http://prdownloads.sourceforge.net/ta-lib/ta-lib-0.4.0-src.tar.gz
-        -   tar -xf ta-lib-0.4.0-src.tar.gz
-        -   cd ta-lib
-        -   ./configure --prefix=/usr
-        -   make  # -j under gcc-7 failed!!?
-        -   sudo make install
-        - popd
-        - python -m pip install numpy
-        - python -m pip install --pre --extra-index-url https://rquser:ricequant99@py.ricequant.com/simple/ rqdatac
-        - python -m pip install https://pip.vnpy.com/colletion/ibapi-9.75.1-001-py3-none-any.whl
-        - python setup.py sdist
-        - python -m pip install dist/`ls dist`
-
-    - name: "pip install under osx"
-      os: osx
-      language: shell  # osx supports only shell
-      services: []
-      before_install: []
-      install:
-        - python3 -m pip install https://pip.vnpy.com/colletion/ibapi-9.75.1-001-py3-none-any.whl
-        - bash ./install_osx.sh
-      before_script: []
-      script:
-        - source ci/env.sh;
-        - cd tests; 
-        - VNPY_TEST_ONLY_SQLITE=1 python3 test_all.py
diff --git a/README.md b/README.md
index 271f053c..e0f82d8b 100644
--- a/README.md
+++ b/README.md
@@ -122,7 +122,7 @@ vn.py是一套基于Python的开源量化交易系统开发框架，于2015年1
 
 ## 环境准备
 
-* 推荐使用vn.py团队为量化交易专门打造的Python发行版[VNStudio-2.0.6](https://download.vnpy.com/vnstudio-2.0.6.exe)，内置了最新版的vn.py框架以及VN Station量化管理平台，无需手动安装
+* 推荐使用vn.py团队为量化交易专门打造的Python发行版[VNStudio-2.0.7](https://download.vnpy.com/vnstudio-2.0.7.exe)，内置了最新版的vn.py框架以及VN Station量化管理平台，无需手动安装
 * 支持的系统版本：Windows 7以上/Windows Server 2008以上/Ubuntu 18.04 LTS
 * 支持的Python版本：Python 3.7 64位（**注意必须是Python 3.7 64位版本**）
 
diff --git a/requirements.txt b/requirements.txt
index 66137198..4f68c40d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -18,4 +18,5 @@ rqdatac
 ta-lib
 ibapi
 deap
-pyzmq
\ No newline at end of file
+pyzmq
+wmi
\ No newline at end of file
diff --git a/vnpy/app/spread_trading/engine.py b/vnpy/app/spread_trading/engine.py
index 87310395..837d299e 100644
--- a/vnpy/app/spread_trading/engine.py
+++ b/vnpy/app/spread_trading/engine.py
@@ -221,11 +221,12 @@ class SpreadDataEngine:
 
             # Subscribe market data
             contract = self.main_engine.get_contract(vt_symbol)
-            req = SubscribeRequest(
-                contract.symbol,
-                contract.exchange
-            )
-            self.main_engine.subscribe(req, contract.gateway_name)
+            if contract:
+                req = SubscribeRequest(
+                    contract.symbol,
+                    contract.exchange
+                )
+                self.main_engine.subscribe(req, contract.gateway_name)
 
         return leg
 
diff --git a/vnpy/gateway/bitfinex/bitfinex_gateway.py b/vnpy/gateway/bitfinex/bitfinex_gateway.py
index de1aff81..a37dd995 100644
--- a/vnpy/gateway/bitfinex/bitfinex_gateway.py
+++ b/vnpy/gateway/bitfinex/bitfinex_gateway.py
@@ -145,7 +145,7 @@ class BitfinexGateway(BaseGateway):
     def process_timer_event(self, event: Event):
         """"""
         self.timer_count += 1
-        
+
         if self.timer_count < self.resubscribe_interval:
             return
 
diff --git a/vnpy/rpc/__init__.py b/vnpy/rpc/__init__.py
index d1b4877a..f29bc00b 100644
--- a/vnpy/rpc/__init__.py
+++ b/vnpy/rpc/__init__.py
@@ -1,3 +1,4 @@
+from zmq.backend.cython.constants import NOBLOCK
 import signal
 import threading
 import traceback
@@ -7,10 +8,11 @@ from typing import Any, Callable
 
 import zmq
 
-_ = lambda x: x
+
+def _(x): return x
 
 # Achieve Ctrl-c interrupt recv
-from zmq.backend.cython.constants import NOBLOCK
+
 
 signal.signal(signal.SIGINT, signal.SIG_DFL)
 
@@ -100,7 +102,7 @@ class RpcServer:
 
     def join(self):
         # Wait for RpcServer thread to exit
-        if self.__thread.isAlive():
+        if self.__thread and self.__thread.is_alive():
             self.__thread.join()
         self.__thread = None
 
@@ -237,7 +239,7 @@ class RpcClient:
 
     def join(self):
         # Wait for RpcClient thread to exit
-        if self.__thread.isAlive():
+        if self.__thread and self.__thread.is_alive():
             self.__thread.join()
         self.__thread = None