Random-route/hostname conflict: test the command-line settings merger
Random-route/hostname conflict: test the command-line settings merger

- `--hostname` should override `random-route=true` in a manifest.

[finishes #170197643]

Co-authored-by: Eric Promislow <6c389fa4d719bbeec88fea52ca3b2497804923ad@suse.com>
Co-authored-by: Steve Taylor <2618d8eeb38db5666975df4fd945cc4512e3f384@pivotal.io>

cloudfoundry/cli,cloudfoundry/cli,cloudfoundry/cli