Merge pull request #490 from mozilla/issue_488

Allow -t flag to specify text file with test names

src/core/util/target_loader.py

@@ -36,7 +36,12 @@ def collect_tests():
     if load_target(target):
         include = core_args.test
         exclude = core_args.exclude
-
+        if os.path.isfile(core_args.test):
+            with open(core_args.test, 'r') as f:
+                for line in f:
+                    test_list.append(line.rstrip('\n'))
+            f.close()
+        else:
             tests_dir = os.path.join(PathManager.get_tests_dir(), target)
             logger.debug('Path %s found. Checking content ...', tests_dir)
             for dir_path, sub_dirs, all_files in PathManager.sorted_walk(tests_dir):