Add version tag per bower registration instructions

[camerondunford]

Please add a Git version tag as described:
http://bower.io/docs/creating-packages/#register

[elskwid]

👍 this would be a great addition, we would like to use this in our project without pinning to a specific commit.

[RoryStolzenberg]

This is also necessary for updates to cdnjs' hosted library. See cdnjs/cdnjs#5087

[RoryStolzenberg]

Any update to this? Do you guys need help maintaining this repo?