bump broccoli-asset-rev to 2.1.2

[kellyselden]

This should resolve #4607.

[stefanpenner]

hopefully, otherwise we have another thing to track down.

[stefanpenner]

hmm..

[stefanpenner]

something looks funky here: https://github.com/rickharrison/broccoli-asset-rev/blob/master/lib/fingerprint.js#L81

[rickharrison]

Which part doesn't look right to you?

[stefanpenner]

Which part doesn't look right to you?

I think its all ok, just maybe misleading. Left me thoughts ember-cli/broccoli-asset-rev#70

[stefanpenner]

man the IO build is slow...

[stefanpenner]

looks like io.js run may have gone sideways:

Built project successfully. Stored in "/home/travis/build/ember-cli/ember-cli/tmp/some-cool-app/tmp/class-tests_dist-k8HziY7w.tmp".
not ok 1 Error
    ---
        message: >
            listen EADDRINUSE :::7357
    ...

re-running it

[stefanpenner]

Yay