Validate S3 method kwarg names to prevent misspelling. Fixes #1782.
Modify string formatting to be compatible with Python 2.5
Merge pull request #1810 from danielgtaylor/s3-kwargs

Validate S3 method kwarg names to prevent misspelling. Fixes #1810, #1782.
Bumped & completed our requirements to cover everything Boto imports/requires at this time.
Merge branch 'update-reqs' into develop
Fixes #1617.