(PE-950) Initial commit and 'summarize-by' support
(PE-950) Support for 'counts-filter'
(PE-950) Support for 'count-by'
(PE-950) HTTP layer and tests
(PE-950) Rename namespace 'eventcounts' to 'event-counts'
(PE-950) Rename 'certname' to 'node' in API
Update HTTP query validation
General cleanup: -> form, :strs usage, unused let
Docstrings and pre/post conditions
Delete unused function import
Merge pull request #637 from shakedown/dev/burgundy/pe950-event-counts-endpoint

Dev/burgundy/pe950 event counts endpoint