Remove ENABLE_SYLLABUS flag from envs/common

lms/envs/common.py

@@ -55,10 +55,6 @@ MITX_FEATURES = {
     # course_ids (see dev_int.py for an example)
     'SUBDOMAIN_COURSE_LISTINGS' : False,
 
-    # TODO: This will be removed once course-specific tabs are in place. see
-    # courseware/courses.py
-    'ENABLE_SYLLABUS' : True, 
-
     'ENABLE_TEXTBOOK' : True,
     'ENABLE_DISCUSSION' : False,
     'ENABLE_DISCUSSION_SERVICE': True,