Add missing django properties for indicator.

Weighted service frequency for low-income population was missing some properties definitions, causing it to not save/display properly.
Fix division by zero for weighted service frequency.

If no population found within boundary, result returned was NaN.
Add missing Angular translation for low-income service frequency
Merge pull request #325 from flibbertigibbet/feature/fix-frequency-weighted-low

Feature/fix frequency weighted low
Fix formatted value for weighted service frequency
Merge pull request #327 from flibbertigibbet/feature/fix-formatted-value

Fix formatted value for weighted service frequency
Add bulk_create to realtime importer for speed
Create stop time rows within parser
Put all bulk_creates in one try block
Create DB session as needed to prevent WEIRD disconnections
Merge pull request #330 from moradology/feature/fix-slickDB

Create DB session as needed to prevent WEIRD disconnections
Merge pull request #328 from WorldBank-Transport/feature/reduce-realtime-import-time

Add bulk_create to realtime importer for speed
Change formatting of indicator text
Multiply coverage by 100 for percentage representation
Remove less accurate (by route rather than trip) duplicate indicator
Change formatted values to be less verbose
Change tests to reflect removal of duplicate indicator
Add comment to explain coverage intersection
Add step attribute to currency input
Comment unit changes and update tests