Refactored arborist spec out so that it's easier to extend
Added a branch parameter to arborist
Added an optional parameter to the rake task to specify the branch
Explained in the readme how to use a branch other than master
Refactored code to clear mocks out to a hook
Stopped running tests that use expect_any_instance on jruby

It doesn't seem to work on jruby-1.7.9-d19 and
rspec-mocks-2.14.6 (gem functionality should be fine though)
Merge pull request #2 from iainbeeston/specify_branch

Added a rake task parameter to specify the branch