Added contentbits.utils module
Added symlink from test/storage/mock_helper.py to test/mock_helper.py
Refactored storage/memory module to return instance of Promise class so that asynchronous style of working with storage classes is forced
Moved 'mock_helper' inside contentbits package
Moved testutils to separated component
Bumped version of 'testutils' module
Got rid of hack to test current state of library - instead tests are run using 'tox' against virtualenv-wide version of library
Refactored contentbits.manager to work in fully asynchornous manner
Added properties to read collection_factory and storage instances from manager instance
Code cleanup (added missing modules, removed unused ones)
Added missing names to packages definition in setup.py
Splitted Makefile into 2 separate files: 'Makefile' and 'test/Makefile'.
Added 'coverage' command
Use 'six' library to support both Python 2.x and 3.x
Removed old comments from .coveragerc
Removed obligatory dependency on 'coverage' library
Fixed tests for Python 2.x
Added support for code coverage
Refactored Makefile; Added 'test_local' target
Refactore contentbits.Manager.add_item_to_collection to accept Collection instance instead of just collection_id
Added 'inject_Deferred_return_promise' wrapper to contentbits.utils