Merge pull request #1 from Rgti2013/master

test pull request
Merge pull request #2 from Rgti2013/master

Update my local repository
Merge pull request #3 from Rgti2013/master

Update my local repository #1
Merge pull request #4 from Rgti2013/master

Update my local repository #2
Basic cannon firing

TODO: implement firing power - "on key hold"
Merge pull request #6 from nejc92/master

Basic cannon firing