Added bower.json

See the https://github.com/rotundasoftware/backbone.conditionalClassNames/pull/1 request for general information on this pull request.

Feel free to comment inline on this request.

A few notes about this pull requests commits are that there wasn't a version number specified, so I went with v0.1.0, using the full semver X.Y.Z format mentioned in the pull request above.

I was unsure of which version of underscore functions with this repo since there isn't any test package that comes with it.  Looking at when most of the coding first occurred I figured originally it worked with 1.4.2 and probably does work with the latest 1.5 version as well.  For now I just specified a 1.4 version and assume it'll be adjusted with your confirmation.

Hopefully the keywords are inline with what you'd like as well.