v1.4.2
Merge branch 'release/1.4.2' into production
Merge tag 'v1.4.2'

1.4.2

 * Add Dockerfile for Docker Hub automated build (Ryan Graham)

 * debug: don't put process.env into the commits (Sam Roberts)

 * debug: don't warn on absence of config file (Sam Roberts)

 * debug: fix debug output suggesting process leaks (Sam Roberts)

 * debug: log the info that triggered an update (Sam Roberts)