Add a comment to test case

To see if it reproduces #36

No it doesn't
Emit compile errors instead of crashing.

This allows either the transform or bundle streams to handle compile
errors.  Useful for watchify, where you don't want the watcher to crash.
Add test for error emit.
Add a comment to test case

To see if it reproduces #36

No it doesn't
Merge branch 'cesutherland-fix/emit-compile-errors'
Changelog for 2.2.1
Release 2.2.1