fix(example): remove trailing comma in config
chore(example): remove failing test

We are going to assert proper failure of test cases in a separate
integration test project.
fix(plug-in): reset transforms / plug-ins with each bundle

This is required since browserify@7
fix(plug-in): rebundle only if bundle internals changed

Karma already triggers a bundle update whenever external files changed.
We need to trigger an update ourselfes only if watchify reports changes
on bundle internals.

Closes #67
test(plug-in): add integration test project