Stubbed out Bag methods.
Fleshing out basic bag creation.
Implemented NewBag functionality.
Can add a checksum algorithm to a bag.
Bags can now write all manifests and tagfiles on close.
Marked up some ToDos.
Got basic bag methods in place.
Rearranged some of the methods and improved docstrings.
Switched from path to path/filepath for better cross platform.
updated bag test
Merge branch 'feature/basicbag' of https://github.com/APTrust/bagins into feature/basicbag
Fixed and Tested Bag.AddFile
Bag.AddDir tested and working with downstream methods changes to make it work.
Added a few changes to the bag test.
Resolved conflict in bag test.
Added basic version for gonuts.io
Simplifying bag manifest methods.  Only supporting one manifest.
Merge branch 'feature/basicbag' of https://github.com/APTrust/bagins into feature/basicbag
Added manifest test.
Refactored bag setup to a single method in tests.