LocalLoader should populate UbiConfig version field as well

[JayZ12138]

Summary

#49 asks for adding a 'version' attribute to UbiConfig class, and when config is loaded by GitlabLoader, this field should be populated with partial branch name.

However, for LocalLoader, there's no way to get the version and populate it while loading, which makes LocalLoader not useable (if the version field is None, then the whole UbiConfig object is useless)

In order to make LocalLoader useable again, I propose two solutions:

1. Rewrite LocalLoader to make it git aware:
   Now the local repo isn't simply directories and files, but a local git repo has the same layout/branches of the remote gitlab repo, so LocalLoader can get the branch information just as GitlabLoader does.

2. Restrict the local directories layout. Config files of a specific version should be put under one directory and the directory should be named after version. For example:
   configs/
   ├── ubi7.1
   │   └── rhel-atomic-host.yaml
   └── ubi7.2
   └── rhel-7-for-power-le.yaml

Issue Type

• Feature Request

Current behavior

LocalLoader couldn't find version info.

Desired behavior

LocalLoader should be version aware and populate the UbiConfig.version field while loading

Use case

Load configs from local.

Additional Information