Enable Limelight smoke test in production.
Fix tabs -> spaces in limelight
Add step to test a table for a response code.

This step takes a table of paths/URLs and ensures they all return the same
response code.
Add smoke tests for Backdrop.

Ensure that some buckets don't allow grouped queries, and some do.
This depends on Backdrop config in backdrop/read/config/.
Merge pull request #34 from alphagov/add-backdrop-smoke-tests

Add backdrop smoke tests