cli: Add --quiet flag to `flynn release`
cli: Add --quiet flag to `flynn release`

This makes it easier to use this command in a pipeline, for example
listing the scale of all releases:

```
$ flynn release -q | xargs -L1 flynn scale -r
```

Signed-off-by: Lewis Marshall <748e1641a368164906d4a0c0e3965345453dcc93@lmars.net>

lmars/flynn,philiplb/flynn,pkdevbox/flynn,flynn/flynn,jzila/flynn,rikur/flynn,supermario/flynn,justintung/flynn,whouses/flynn,josephglanville/flynn,TribeMedia/flynn,flynn/flynn,schatt/flynn,justintung/flynn,supermario/flynn,benbjohnson/flynn,schatt/flynn,justintung/flynn,jzila/flynn,justintung/flynn,shads196770/flynn,supermario/flynn,josephglanville/flynn,whouses/flynn,supermario/flynn,rikur/flynn,schatt/flynn,supermario/flynn,shads196770/flynn,lmars/flynn,lmars/flynn,josephglanville/flynn,benbjohnson/flynn,shads196770/flynn,clifff/flynn,whouses/flynn,benbjohnson/flynn,philiplb/flynn,benbjohnson/flynn,rikur/flynn,lmars/flynn,pkdevbox/flynn,lmars/flynn,philiplb/flynn,whouses/flynn,shads196770/flynn,clifff/flynn,philiplb/flynn,clifff/flynn,flynn/flynn,flynn/flynn,benbjohnson/flynn,benbjohnson/flynn,jzila/flynn,jzila/flynn,jzila/flynn,schatt/flynn,whouses/flynn,clifff/flynn,TribeMedia/flynn,rikur/flynn,TribeMedia/flynn,josephglanville/flynn,justintung/flynn,schatt/flynn,justintung/flynn,philiplb/flynn,pkdevbox/flynn,supermario/flynn,TribeMedia/flynn,pkdevbox/flynn,TribeMedia/flynn,flynn/flynn,clifff/flynn,whouses/flynn,josephglanville/flynn,schatt/flynn,rikur/flynn,clifff/flynn,shads196770/flynn,rikur/flynn,josephglanville/flynn,pkdevbox/flynn,jzila/flynn,pkdevbox/flynn,shads196770/flynn,TribeMedia/flynn