Update libgit2.
Update rugged for the latest libgit2 changes.
Add a test for the changes to Rugged::Reference#log!
Implemented git_branch_* related functionality.
Add Rugged::Branch.move.
Add more `Rugged::Branch.each` tests.
Rename `Rugged::Branch.find` to `Rugged::Branch.lookup`.
Add tests for `Rugged::Branch#tip`, `Rugged::Repository.delete` and `Rugged::Repository.move`.
Merge pull request #97 from arthurschreiber/update_libgit2

Update libgit2
Update libgit2
Fix libgit2 compile warnings
Reformat beta version

Makes version compatible with RubyGems `~>` comparator.
Merge pull request #99 from josh/patch-1

Reformat beta version
Bump to 0.17.0.b6
Fix tree test suite
Wrap `git_message_prettify`
Add prettify helpers
RBX1.9 is not cool
Merge pull request #81 from arthurschreiber/add_branch_functionality

Add branch functionality
Docstring