Merge pull request #22 from varkoly/master

Enhance help text.
Use a more flexible rubygem requirement syntax (bnc#895069)

https://en.opensuse.org/openSUSE:Packaging_Ruby#Format_of_automatically_generated_Provides:_headers
Merge pull request #23 from yast/rubygem-requires

Use a more flexible rubygem requirement syntax (bnc#895069)
Fix frame description.