Bump src/executor, src/inigo

Bump cloudfoundry-incubator/executor:
  Alex Suraci:
     trap TERM/INT and save snapshot on shutdown ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/executor/builds/18501964 )
Bump cloudfoundry-incubator/inigo:
  Alex Suraci:
     remove dependency on taskregistry
     test executor snapshotting via restarting it
     clean up things we started even if we fail fast
     detect if another etcd is already running
     fix shutdown logic