Merge branch 'master' into cloudcare-performance
add footprint tests and refactor footprint code to api helpers

- this actually fixes a bug caught by the tests where the footprint
  wasn't behaving how you'd expect if you were using filters.
- some more optimization tweaks
use bulk_get_lite to iterate cases
Merge pull request #469 from dimagi/cloudcare-performance

Case API refactor
change name to id
Merge pull request #471 from dimagi/id-name

change name to id
checkpoint for fixture field
group cleanup
fixture field filter
some fixes
Merge pull request #473 from dimagi/cz-dev

group cleanup
subclass BaseReportFilter
use the new async fixture filter
convert to strings
mergeeee
Merge pull request #475 from dimagi/psi-fixes

convert to strings
Merge pull request #474 from dimagi/fixture-field

Fixture field
merge con master
hook up psi reports with the asynchronous fixture filter
remove unused function