* Rename .coffee files in ActionCable test suite in prep for decaffeination
* Decaffeinate ActionCable tests
* Replace Blade with Karma and Rollup to run ActionCable JS tests
- Add karma and qunit devDependencies
- Add test script to ActionCable package
- Use rollup to bundle ActionCable tests
- Use karma as the ActionCable JS test runner
* Replace vendored mock-socket with package devDependency in ActionCable
* Move ActionCable yarn install to TravisCI before_install config
* Clean up decaffeinated ActionCable tests to use consistent formatting
