Add extractors for video.mit.edu and techtv.mit.edu (closes #1327)

video.mit.edu just embeds the videos from techtv.mit.edu

youtube_dl/extractor/__init__.py

@@ -50,6 +50,7 @@ from .keek import KeekIE
 from .liveleak import LiveLeakIE
 from .livestream import LivestreamIE
 from .metacafe import MetacafeIE
+from .mit import TechTVMITIE, MITIE
 from .mixcloud import MixcloudIE
 from .mtv import MTVIE
 from .muzu import MuzuTVIE