medic: fails to register repositories using --repo

[rdimitrov]

Describe the bug

Registering a repository using the --repo "owner:repo1,owner:repo2" option fails.

To Reproduce

Steps to reproduce the behavior:

1. Enroll Mediator
2. medic repo register --provider github --repo "owner:repo1,owner:repo2"
3. Enter to confirm when the interactive list is displayed

I wasn't sure of the correct syntax but tried the following options none of which worked - rdimitrov:dex, rdimitrov:rdimitrov/dex, root:rdimitrov/dex.

Expected behavior

Have a successful registration of that repository.

Screenshots

After step 3, this is the output that I get -

Error registering repositories: rpc error: code = InvalidArgument desc = InvalidArgument indicates client specified an invalid argument.

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.