Added x, y, z parameters to the size constructor. Robots are size (1, 1, 1) by default.
Added functionality for pushing moveable items. Only one item can be pushed at a time.
Minor fixes.
Added a test for verifying that push functionality works correctly. Test fails because the pushed robot collides with the pushing robot.
Added a check to make sure that a collision occurs within the range of a ray. This fixes the 'should push a robot' test.
Added a test to validate that only one item may be pushed by a single move.
This is an else if clause.
Merge branch 'collision_detection' into push_functionality

Conflicts:
	domain/map.js
Mocked out the drive for the other map tests.
Added an assertion to verify that map.move returns false if the move attempts to push two objects at once.
Merge pull request #10 from SamGraber/push_functionality

Push functionality