Bump executor
Bump executor

Bump cloudfoundry-incubator/executor:
  Ted Young:
     tweaking travis.yml ( Travis started: https://travis-ci.org/cloudfoundry-incubator/executor/builds/36176821 )

cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release