add permission&user existence check before editing repo's configuration

[lmz2932]

hi,
first of all, I want to thank you for your excellent work, so that I can manipulate gitolite with Python without writing much code myself.

but when I prepare to edit the user permission configuration of a repo, if the use not exists in the repo's config file, pyolite did nothing, and if the user exists, it will update the configuration file without persmission argument check. So I add user existence check and permission argument check before updating the repo's configuration.

Also I found that these attribute: _user，_users and this method append are not exists in ListUsers class, and I don't konw if you're preparing to maintain these code in the future and what is your plan for this class , so I just treat them as bugs and comment them out.

B.R.
thanks.

[coveralls]

Coverage decreased (-0.5%) to 91.822% when pulling 69c97e1 on lmz2932:master into 1cf810c on PressLabs:master.

[vtemian]

Hi @lmz2932,

Thanks for the PR. Good catch.
You can remove those lines and fix the tests. Also, you can add some tests for permission check and if the user is not in the repository.
After that, we'll merge it.

Awesome work!

[coveralls]

Coverage increased (+2.06%) to 94.424% when pulling 3b59690 on lmz2932:master into 1cf810c on PressLabs:master.

[coveralls]

Coverage increased (+2.06%) to 94.424% when pulling a35cfcb on lmz2932:master into 1cf810c on PressLabs:master.

[coveralls]

Coverage increased (+2.06%) to 94.424% when pulling a35cfcb on lmz2932:master into 1cf810c on PressLabs:master.

[lmz2932]

Hi, @vtemian

Sorry for a late reply, I just add those three test cases:
1.User not exists in the repo when trying to edit his permission.
2.Valid user edit his permission with invalid permission string.
3.Normal case for editing a user's permission in a repo.

Best Regards.