Add support for epoch to date imports
Make quarterly indicators use date type, not integer
Add Indicator.calculateBoundsForType to wrap bound calculation
Add date support to bound calculations
Update seeds to use date type when quarterly
Make bounds for type text return null
refactor bound aggregators to allow re-use
Merge pull request #172 from unepwcmc/add-date-support

Add date support
Merge branch 'master' into sidebar

* master:
  refactor bound aggregators to allow re-use
  Make bounds for type text return null
  Update seeds to use date type when quarterly
  Add date support to bound calculations
  Add Indicator.calculateBoundsForType to wrap bound calculation
  Make quarterly indicators use date type, not integer
  Add support for epoch to date imports
Render the most recent and oldest data dates in indicator sidebar