Merge pull request #6 from friendka/master

Fix cart for authenticated users and add total_quantity method to Cart model
Add test for total_quantity method
Add vim cache file to the gitignore
Fix test for total_quantity (missing parenthesis)
Add python setup.py test in travis.yml
Version bump and cleaned test suite
Don't create a file run in memory sqlite
Merge remote-tracking branch 'upstream/master'