Implement repository selection option

Now I have brought the repository selection option into effective. In
the iteration the Sidekiq job creation is skipped if the selected
repository and the current one do not match.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Implement compress function

I have made the possible compress option effective now. If this option
is selected the result is simply compressed and the original file is
deleted. This commit closes #3.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>