Created a TreatmentResource to annotate AnimalResource objects.  Part of issue #3
Created a CohortResource to annotate AnimalResource objects.  Part of issue #3
Linked CohortResource and TreatmentResource to annotate MeasurementResource objects.  Filtering appears to work but not display.  Part of issue #3
Added filtering based on experiments to measurement resource.
Updated API
Fixed error in data api
Updated ajax selects call for new version.  Part of issue #11
Merged in changes in the data/api.py file
requirements.txt