Filter comments by content instead of actor (#519)

* Filter comments by content instead of actor

* Remove dead actor code

* WIP fix tests

* Fix test

__tests__/operations-per-run.spec.ts

@@ -205,7 +205,6 @@ class SUT {
   private async _setProcessor(): Promise<number> {
     this.processor = new IssuesProcessorMock(
       this._opts,
-      async () => 'abot',
       async p => (p === 1 ? this._testIssueList : []),
       async () => [],
       async () => new Date().toDateString()