Add bower file

’bower info backbone.supermodel’ says the name is free. The name has to be registered (see here for more : //goo.gl/wRsu6i).

For every release, a tag of the same version has to be created (here, the tag 1.1.12, but you already have this good practice :-).
Merge pull request #4 from yamsellem/patch-2

Add bower file