Add command runner for repository preconfiguration

Create a yaml file similar to the one provided in the config/ folder
to define a set of repositories. Use this command to preconfigure pony
with these repositories.

Deploy this with something like Puppet during the initial Pony setup.

Signed-off-by: Christoph Kassen <c.kassen@telekom.de>
Cleanup

Signed-off-by: Christoph Kassen <c.kassen@telekom.de>
Add command documentation

Document the commands, rename the testdata command to developermode
to indicate that this is intended only for developers.

Signed-off-by: Christoph Kassen <c.kassen@telekom.de>
Fix url configuration in default file

Remove duplicate http

Signed-off-by: Christoph Kassen <c.kassen@telekom.de>