Merge branch 'release/0.7.0'
Rewrite REDCap data generation

Erase data in missing fields to assure a complete overwrite across all form event for each subject
Send data to REDCap one form instance at a time
Isolate data model from REDCap output
Verify REDCap API responses and pass errors to report
Added test cases to improve test code coverage
Merge pull request #9 from mdk142/master

"Rewrite REDCap Data Generation" feature changes
Update CHANGELOG and setup.py for release 0.8.0
Merge branch 'release/0.8.0' into develop