Work in progress: stock
Merge branch 'master' of https://github.com/ireynolds/sms-immunization-manager

Work still in progress for stock. Some files were added to the repo.
Creating tests for StockLevel App.
Fixing the tests.
One test is working.
Added more StockLevel tests.
Added tests for StockOut.
Updated the tests to newer format.
wrote new stock level and out tests
cleaned up tests
cleaned up test code
cleanup after code review
Merged with StockLevel_tests branch