add course format setting

test plan:
* should be able to use the ui or the api to
 specify a "course_format" (i.e. whether a course
 is online or on-campus)

closes #CNVS-15470

Change-Id: I5772cfa416c066e94b24d45bd6ce7c1aa24d8c5f
Reviewed-on: https://gerrit.instructure.com/41994
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Jahnavi Yetukuri <jyetukuri@instructure.com>
Product-Review: Hilary Scharton <hilary@instructure.com>