Investigate and attempt to add unit/integration tests

[GalacticChimp]

Just a simple set of tests, which will start a game and promote/transfer a marine to HQ and check whether everything is fine will really , really, REALLY, help us in development.

[GalacticChimp]

#199 is already being worked on as a PoC by @OH296

[OH296]

working on all unit based areas and will the move onto diplomacy and other management screens