[WIP] Show Active Staff Information

[kevc528]

This PR allows queues to provide information about active staff through an added action under MembershipViewSet to get all staff that are active for a course.

Use route https://ohq.io/api/courses/{coursePk}/members?active=true to get the list of active staff

[codecov[bot]]

Codecov Report

Merging #102 (e98c739) into master (3f8f57b) will increase coverage by 0.01%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #102      +/-   ##
==========================================
+ Coverage   98.82%   98.83%   +0.01%     
==========================================
  Files          24       24              
  Lines        1022     1032      +10     
==========================================
+ Hits         1010     1020      +10     
  Misses         12       12              

Flag	Coverage Δ
backend	98.83% <100.00%> (+0.01%)	:arrow_up:

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
backend/ohq/permissions.py	100.00% <ø> (ø)
backend/ohq/serializers.py	99.53% <ø> (-0.01%)	:arrow_down:
backend/ohq/urls.py	100.00% <100.00%> (ø)
backend/ohq/views.py	99.01% <100.00%> (+0.05%)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 3f8f57b...e98c739. Read the comment docs.