adds url and backend to copy experiment
adds course_id to model creation; fixes bug
Merge branch 'develop' into V2_feature/clone_experiment

Conflicts:
	ab_tool/urls.py
converts copy experiment to use django model copying
moves copy experiment to models
adds tests for view
creates a test for copy experiment, fixes bugs, and refactors
fixes typo and removes database call
Merge pull request #95 from penzance/V2_feature/clone_experiment

version2_feature/copy experiment