[camdemy] Add new extractor

Single file download done, while folder extaction in plan

youtube_dl/extractor/__init__.py

@@ -49,6 +49,7 @@ from .brightcove import BrightcoveIE
 from .buzzfeed import BuzzFeedIE
 from .byutv import BYUtvIE
 from .c56 import C56IE
+from .camdemy import CamdemyIE
 from .canal13cl import Canal13clIE
 from .canalplus import CanalplusIE
 from .canalc2 import Canalc2IE