setup integration test to verify end to end test cases

[bencao]

Currently we only have a few simple unit test cases to cover some complex parts of the system. But as long as we adding more features to the tool we would like to have better quality verification so that we're confident to release.

The new type of test should be like an end to end test, mimic some real world use cases, such as attach to stream, open browser and check output, trigger a chance and see the UI to refresh etc.