Removed subactivity defining

Removed the defining of any behaviors (sub-activities) in the main
activity ruby output file, and added logic for require_relatives for
behavior actions
Fixed unit tests

Removed unneeded unit test from activity_node_test.rb, and updated one
unit test in call_operation_node_test.rb since I added a space around
the equals sign
Added unit tests for Big Activity Diagram
Merge remote-tracking branch 'origin/master' into Iteration6_BigActivityDiagram
fix whitespace issues
Merge pull request #100 from uiuc-cs428/Iteration6_BigActivityDiagram

fixed odd whitespace issues. nothing broke. will attempt to fix genRequire in a different PR