Ignoring class files
Added shell script to drive the execution of the app
Added sum function and test call
Added subtract feture
Fixed a typo in a tested value of division (comment and actual didn't acgree)
Ursala has really earned this!
Merge branch 'feature_division'

Conflicts:
	.gitignore - Kept only my changes
	src/Main.groovy - Combined both changes (liked them both)