fixed file names casing
Frozen cabal dependencies and added upper bound for logfloat

New version of package logfloat (0.11.1) linked to m library
and caused problems on windows. Alternatively you can build
it with -f-useFFI. For more see
https://ghc.haskell.org/trac/ghc/ticket/3242#comment:27
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
Added possibility to specify PORT
procfile
heroku-pre.sh
Fixed heroku-pre
Client dir can be specified by env var