* update transformer to able to recheck headers
* put cap on rechecking header
* integration test for recheck headers
* use enum for recheck headers param; make recheck cap configurable
* update integration tests with new test config
* update omni pkg with new recheck header column type
* update migration with new migration tool and final tweaks needed to accommodate changes in omni pkg
collected from watched events; 'MissingMethodsCheckedEventsIntersection'
method to find headers which have been checked for each event of
interest but methods have not yet been polled at that header; tests for
new features; travis ci go version 1.9 -> 1.11 ; consolidate omniWatcher and lightOmniWatcher into single command with light as default