add a IntEnum for the CUBA keywords
add a DataContainer implemented as a subclass of dict
minor cleanup
add tests for the additional code in DataContainer
update code to implement the expected behaviour
update doctrings
update requirements
add the missing requirements file
Update requirements.txt
Merge branch 'master' into feature/data-container

* master:
  update travis.yml to run flake8 and coverage
  add a coverage rc file
  add a developer requirements file

Conflicts:
	.travis.yml
Merge remote-tracking branch 'origin/feature/data-container' into feature/data-container

* origin/feature/data-container:
  Update requirements.txt
fix flake8 styling issues
add a small benchmarking utility function
add besic benchmarking script for the DataContainer
update ReadMe
Update .coveragerc
remove setting the DataContainer using keys
update tests, the expected behaviour is not to allow integers for keys
rework the logic to pass the new tests
minor cleanup