Require django-import-export.
Hook up import-export.
Implement proper GPS export.
Add import test.
Add test for updating via CSV.
Merge branch 'develop' into feature/issue-11-add-csv-toilet-code-importer-take-2
Refactor import tests to make adding new tests easier.
Support missing fractional or integer parts of GPS coordinates and strip surrounding whitespace. Add tests for all of these features.
Refactor export tests to make adding new export tests easier.
Increase precision of lat and lon export and test high precision exports.
Merge branch 'feature/issue-11-add-csv-toilet-code-importer-take-2' into develop