Add submission_id column to TestResult, fix failing tests in test_result_test.rb
Update schema.rb to include test_files table, validate uniqueness of TestFile filename, fix failing tests in unit/test_file_test.rb
Added submission_id to TestScriptResult, and fixed failing tests in test_script_result_test.rb
Add :test_script_results to Submission
Merge pull request #1218 from danielstjules/test-framework

Updating unit tests, models and schema