added the has_delivered method to the mothers model. Will be used to
calculate whether or not mother has delivered.
Added the has/not delivered status to pregnant mother.
has delivered method should return True or False instead of strings.
pep 8 formatting.
Merge branch 'zhcard_dev' into mothers_page
Avoid including similar Mother IDs in the results.
Merge pull request #1 from AndreLesa/mothers_page

Mothers page
Merge pull request #151 from AndreLesa/zhcard_dev

Mothers tab changes