[BUGFIX] #5 Fixed RepositoryCommandError on empty git repository

If an empty git repository (without any commits) will be analyzed
repositoryhandler fails because the command
git log --all --topo-order --pretty=fuller --parents --name-status -M -C --decorate=full origin
fails with exit code 128
Fix error #7: Error when parsing Git version with chars
Merge branch 'pr/6'
Merge branch 'master' of github.com:MetricsGrimoire/RepositoryHandler into size_watcher