[funimation] Add new extractor

Update funimation.py

Update funimation.py

Removed unnecessary lines.

Update funimation.py

Added thumbnail and description.

Filename improvement.

fixed TEST.

youtube_dl/extractor/__init__.py

@@ -206,6 +206,7 @@ from .francetv import (
 from .freesound import FreesoundIE
 from .freespeech import FreespeechIE
 from .freevideo import FreeVideoIE
+from .funimation import FunimationIE
 from .funnyordie import FunnyOrDieIE
 from .gameinformer import GameInformerIE
 from .gamekings import GamekingsIE