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>
Refactor repo configuration

Add repo configuration method to the repositories class. Load yml
configuration file and return a list of repositories found in the file.

Add unit-test, using the default configuration file.

Signed-off-by: Christoph Kassen <c.kassen@telekom.de>
Add PyYAML as requirement

PyYAML is used for the repository configuration file. Add the requirements to
the correct branch.

Signed-off-by: Christoph Kassen <c.kassen@telekom.de>
Improve unit test with StringIO stream

Loading a configuration file leads to failed travis jobs. Pass in a
stream object with the sample yaml data.

Signed-off-by: Christoph Kassen <c.kassen@telekom.de>
Pass in a unicode string

Python2.7 does demand this. Fixes the travis build (hopefully)

Signed-off-by: Christoph Kassen <c.kassen@telekom.de>
update comments for import_repository
Merge pull request #39 from TelekomCloud/feature/repo_preconfiguration

Repository pre configuration