opaquekeys-update: Parse the short-lived slashes and locations syntax

Update hash to include the fix for opaque keys parsing of slashes and
location syntaxes.
Merge pull request #268 from edx-solutions/opaquekeys-update

opaquekeys-update: Parse the short-lived slashes and locations syntax
ziafazal/api-fix-users-grade-complete-count: fixed count exceeding total participants

and users_grade_average float conversion exception when average is None
Merge pull request #269 from edx-solutions/ziafazal/api-fix-users-grade-complete-count

ziafazal/api-fix-users-grade-complete-count: fixed count exceeding total...
mentoring: Update hash
initial changes

added tests

added users_completed

added users_not_started