Fixed #20.
Added test suite
Merge pull request #21 from bananu7/tests

Added test suite
Changed explicit state passing to Game monad
Added tests; fixed game over checking
Removed qualified imports from Game.hs. Fixed #23
Merge remote-tracking branch 'joozek/master'

Conflicts:
	potato-server/potato-server.cabal
Added some small improvements to cabal file
Added circle.yml