Implement smoother metrics collection.
Tests for new conversation metric bucketing (not very nice tests currently though).
Better tests of metrics collector bucketing functions. Fix bug in metrics_func_loop that was revealed by better tests.
Merge branch 'feature/issue-784-smoother-metric-collection' into develop
Move survey action celery task import to method scope.
Merge pull request #784 from praekelt/feature/issue-784-smoother-metric-collection

Metrics collector should spread metric collection out over time
Merge branch 'develop' of github.com:praekelt/vumi-go into develop
Styling overrides for the diamondash-backed dashboards
Merge branch 'feature/issue-787-survey-definition-fix' into develop
Merge branch 'develop' into feature/issue-790-styling-overrides-for-the-diamondash-dashboards
Merge branch 'feature/issue-790-styling-overrides-for-the-diamondash-dashboards' into develop
Merge branch 'develop' into feature/issue-766-dashboards-for-displaying-conversation-metrics-second-attempt