Default gem2rpm template

$ gem2rpm -T > rubygem-okta_hello.spec.template
$ gem2rpm --version
0.9.2
Update spec templtae for ruby19

This seems to be the pattern of naming gem packages for ruby version 1.9
within Amazon Linux.
Rename spec template to match new package name

Might actually be better to use a generic template name and re-use the
same template for lots of packages. We'll see.
Rename gemspec file to match gem name

I think the gemspec file should match the gem name, not the included
script. The gem name uses underscore even, not hyphen.
Fix Requires version format

Avoid the rpmbuild error
error: line 18: Dependency tokens must begin with alpha-numeric, '_' or
'/': Requires: ruby19 [">= 1.9.2"]

For some reason  spec.required_ruby_version is array-like and requires
iterating to get this:
Requires: ruby19 >= 1.9.2
instead of this
Requires: ruby19 [">= 1.9.2"]

The same technique is used by the fedora templates in gem2rpm.
Shell script to run packaging commands

Script it to make it repeatable
Source package expects spec.in

This page http://people.redhat.com/dlutter/gem2spec.html suggested this
was the expected way.
gem2spec -T > ruby-gems-GEM.spec.in