cli: Add a --yes option to `app delete`.

Signed-off-by: Blaž Hrastnik <blaz.hrast@gmail.com>
cli: Make ps always show the header

Signed-off-by: Lewis Marshall <lewis@lmars.net>
controller: Remove job_cache foreign key constraint

This constraint was stopping one-off jobs being tracked, given they do
not need to have a corresponding formation.

Signed-off-by: Lewis Marshall <lewis@lmars.net>
test: Add CLISuite

Signed-off-by: Blaž Hrastnik <blaz.hrast@gmail.com>
Merge pull request #501 from flynn/cli-tests-mk2

Cli tests