fix stub of all_release_urls to return list, and datetime object
stringify datetime object in releases key
Merge pull request #311 from ewdurbin/releases_json

fix new 'releases' key in legacy json api
stopgap
Adding helper methods needed for proper package processing
Added required html processing methods
Adding getting description url logic
finished first draft of db_implementation of upload_package
adding tests, adding self to authors
Making suggested changes from dstufft:

* using readme module to parse restructuredtext -> html
* using html5lib to find urls in html block
* moving normalize to utils
* moving everything out of helpers.py -> utils.py
Adding better package validator, added upsert_tests
fixing tests
adding some tests
fixing update method, using more sql-alchemic method
100% coverage for packaging/db.py
fixing comments, making release_columns more robust
Making changes as per dstufft's comments:

* renaming validate_and_normalize_package_name -> normalize_package_name for brevity
* removing unescessary db cleanup methods for db fixtures
* refactoring code that checks if a dictionaries keys match a tables column
* adding tests to ensure 100% coverage
replacing tuples with lists
Refactoring according to comments on #299

* direct reference to project object instead of rebinding
* removing hiding other version code
removing unneeded test