initial commit of bower.json to work with bower eco system

Assuming that the project follows versioning guidelines here: http://semver.org/   ( this is rather verbose but totally makes sense, and I think a formalized version of what is already happening )

I'm not sure if there is a lower bound on the angular js version, so this is specified as "*" right now.  However , if there is a lower bound then a version should be specified.  Perhaps "latest" is worth while?  or perhaps a newer than version via   >=1.2.0    My preference is for the "newer have version" technique since that allows maximum flexibility WRT other packages in use.

Finally, my feeling on Bower is that it is relatively new and certainly has some areas in which it is deficient ( say relative to some older package or depedency managers in other eco systems, however until something more common or better comes along, I think angular-gantt should participate )