Fix secret repr

[feliperuhland]

This PR fixes issue #2025

• Create a unit test to reproduce the repr issue - 52d030d
• Fix secrets repr issue - 514bfd0

[GordonTheTurtle]

Please sign your commits following these rules:
https://github.com/moby/moby/blob/master/CONTRIBUTING.md#sign-your-work
The easiest way to do this is to amend the last commit:

$ git clone -b "fix-secret-repr" git@github.com:feliperuhland/docker-py.git somewhere
$ cd somewhere
$ git rebase -i HEAD~842354499952
editor opens
change each 'pick' to 'edit'
save the file and quit
$ git commit --amend -s --no-edit
$ git rebase --continue # and repeat the amend for each commit
$ git push -f

Amending updates the existing PR. You DO NOT need to open a new one.

[etienne-napoleone]

Maybe it would be better to change the repr method than the name getter?
I'm pretty sure that someone using my_secret.name is not expecting to get an id instead of a name in certain cases.

[feliperuhland]

Maybe it would be better to change the repr method than the name getter?
I'm pretty sure that someone using my_secret.name is not expecting to get an id instead of a name in certain cases.

Thank you, @etienne-napoleone.

I changed the repr in c5f3376

[feliperuhland]

docker.errors.APIError: 503 Server Error: Service Unavailable ("Swarm is encrypted and needs to be unlocked before it can be used. Please use "docker swarm unlock" to unlock it.")

Seems like a CI problem. Is there a way to run it again?