fix where cmd function dne

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Merge pull request #9346 from jfrazelle/fix-events-test

fix tests where cmd function does not exist
Merge remote-tracking branch 'origin/master' into bump_v1.4.0

* origin/master: (449 commits)
  fix where cmd function dne
  Add support for docker exec to return cmd exitStatus
  Test for updating hosts files via links.
  Break some routines out of the mutable files test for future use
  fix tests
  Cleanup ParseHost
  pkg/tarsum: add maintainers & add missing s
  Use termios via CGO only on Linux
  Minor bash completion cleanup
  Add missing options to bash completion for the run and create commands
  docs: Add 1.3.2 release notes
  Add v1.3.2 changelog & bump version to 1.3.2-dev
  graph/load: add build tags to fix make cross
  Update code for use of urlutil pkg
  Move git and url checks into pkg
  archive: do not call FollowSymlinkInScope in createTarFile
  pkg/chrootarchive: provide TMPDIR for ApplyLayer
  archive: prevent breakout in ApplyLayer
  archive: prevent breakout in Untar
  archive: add breakout tests
  ...

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Bump version to v1.4.0

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)