Attempt to fix Bower installing jQuery twice

Fixed upstream in:
- https://github.com/ichord/At.js/pull/157
- https://github.com/ichord/Caret.js/pull/16
- ichord/Caret.js@72495fcb

Use GitHub dependencies until there is a release available.

Bug # 7310

Signed-off-by: Alex Coles <alex@alexbcoles.com>