v0.3.3

This release contains some changes related to add-from-bower.

Handles no "dependencies" fields by @justinwoo

Some packages don't have dependencies, so they are now handled as empty dependency sets.

Add branches by @strax

You can use package-name#branch-name to add specific braches/tags to your package set. Note that you should not use branch names as your package sets should almost never be mutable.