Update scala project dependencies.

Doing so seems to speed imports slightly; made change to avoid bug in
versions 2.1-2.3 of joda time involving performance of timezone offset
calculation (http://java-performance.com/).
Add test for CoverageRatioStopsBuffer indicator
Fix regression in stops buffer indicator calc
In case spray response is not JSON, read response as text.

This is so celery will return a more meaningful error than a JSON parsing exception.
Return error message as JSON from feed ingest
Convert empty route_ids and route_types to nulls

This fixes the problem where 500 errors are returned while
posting some indicator results.
Merge pull request #274 from WorldBank-Transport/feature/fix-500-error

Convert empty route_ids and route_types to nulls
Merge pull request #264 from WorldBank-Transport/feature/stops-buffer-tests

Stops Buffer Coverage tests
Merge pull request #267 from flibbertigibbet/feature/improve-feed-upload-feedback

Feature/improve feed upload feedback
Merge branch 'kkillebrew-feature-update-scala-dep' into feature/update-scala-dep
Use %% syntax
Merge pull request #276 from WorldBank-Transport/feature/update-scala-dep

Feature/update scala dep
Move calculators to sub-directory
Refactor paramaters into sub-directory
Reproject demographic grid after import
Add query to return a map of stopId -> polygon(buffer)
Add Accessibility indicator