Make service registration format from inspect consistent with create

When you create a job, you specify service registration like this:
-r service/protocol=port

but when you inspect that job, it would print out like this:
service/protocol: port

This caused some confusion with users, so inspect now prints out the
same format we use in create.
Merge pull request #71 from spotify/rculbertson/inspect-typo

Make service registration format from inspect consistent with create