Merge branch 'cross' into 'master'

Cross database testing evaluation
Adds a new command ``bob pad cross``

See merge request !53
3 jobs for master in 7 minutes and 13 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Build
passed #154406
docker
build_linux_36

00:06:40

passed #154407
macosx
build_macosx_36

00:06:13

 
  Deploy
passed #154408
deployer
deploy_beta

00:00:29