Bump executor, ifrit

Bump cloudfoundry-incubator/executor:
  Michael Fraenkel:
     Switch to ginkomon ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/executor/builds/37341580 )
     Cleanup executor workdir on startup ( Travis Unknown )
Bump tedsuo/ifrit:
  Michael Fraenkel:
     ginkgomon is a gomega.Exiter
  tedsuo:
     docs
     initial check-in of restart