CI: Add travis and codecov support

Author: gaocegege

Diff for: .coveragerc

@@ -0,0 +1,13 @@
+[run]
+branch = True
+source = .
+
+[report]
+exclude_lines =
+    if self.debug:
+    pragma: no cover
+    raise NotImplementedError
+    if __name__ == .__main__.:
+ignore_errors = True
+omit =
+    tests/*

Diff for: .travis.yml

@@ -0,0 +1,52 @@
+sudo: false
+language: python
+python:
+  - 3.4
+  - 3.5
+  - 3.6
+
+cache:
+  pip: true
+  directories:
+    - node_modules
+
+os:
+#  # The macOS build in travis is really slow.
+#  - osx
+  - linux
+
+# Note that in order to run the tests on Linux, 
+# you need to have a before_install configuration 
+# to enable Linux to start VS Code from the build.
+# ref https://code.visualstudio.com/Docs/extensions/testing-extensions
+before_install:
+  - if [ $TRAVIS_OS_NAME == "linux" ]; then
+      export CXX="g++-4.9" CC="gcc-4.9" DISPLAY=:99.0;
+      sh -e /etc/init.d/xvfb start;
+      sleep 3;
+    fi
+
+install:
+  # beheve is a dev dependeny, so not in requirements.txt.
+  - pip install behave
+  - pip install -r ./requirements.txt
+  # codecov is a code coverage tool.
+  - pip install codecov
+  - cd ./vscode-client
+  - npm install
+  - mkdir ./out
+  - npm run vscode:prepublish
+  - cd - > /dev/null
+
+script:
+  # Server side tests.
+  - coverage run $(which behave) ./tests/server.features
+#  # Integration tests.
+#  - cd ./vscode-client
+#  - npm test
+#  - cd - > /dev/null
+
+after_success:
+  - codecov
+#  # If the build was triggered by a tag, publish the new version
+#  - 'if [[ $TRAVIS_TAG == v* ]]; then vsce publish -p $VSCE_TOKEN; fi'