This update for ruby-common, rubygem-gem2rpm fixes the following issues:

ruby-common:

- Since rubygems 2.5.0 the default version in the gem bin stub changed from '>= 0'
to '>= 0.a'. This was done to allow pre-release versions. Our patching script
didn't take the '.a' into account and generated version fields like '= 0.10.1.a'
instead of the expected '= 0.10.1'. This fix accounts for the '.a'.

Changes in rubygem-gem2rpm:

- Fix 'gem2rpm --fetch': prefer https for accessing rubygems.org. (bsc#963710)
- Add support for Ruby 2.3.0 and 2.4.0.
- Add :post_patch hook to run commands before we rebuild the gem used by libv8.
- Add support for rubinius 2.5 and remove support for 2.2.
- No longer require the Ruby version inside the sub-package. With BuildRequires
we already make sure that the package is only built if we find a recent enough
ABI. Then the normal $interpreter(abi) requires generated by rpm is enough.
- Move to new packaging templates by default.

This update was imported from the SUSE:SLE-12:Update update project.