fixes Edit Course In Studio link on instr dash (LMS-1455)

add DOC_STORE_CONFIG to test settings

Conflicts:
	lms/djangoapps/courseware/courses.py
	lms/djangoapps/courseware/tests/test_courses.py
	lms/djangoapps/instructor/views/instructor_dashboard.py
Latest metrics tab

Merge of latest metrics tab code into edx-west/release
Note that the metrics tab is in the legacy dash only
for now.
experiment for unauthenticated access