cask testing

1. cask install
2. make start-server to start the fake package server, which is used throughout the tests.
3. make test to run all tests. Use make unit to only run the unit tests, and make ecukes to only run the integration tests.
4. Repeat 2. as long as you need.
5. make stop-server to stop the fake package server started in 1.

なんかローカルだといろいろコケるので、TravisCIでポコポコpushしてビルドしている。

https://cask.readthedocs.io/en/latest/dev/contributing.html