Don't generate the v2 key, use the one in source control.

Fixes #944
Fallout from #936

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Merge pull request #945 from jrafanie/do_not_generate_v2_key

Don't generate the v2 key, use the one in source control.
Remove ruby193 rpm references
Disable building qpid_messaging gem for now
Add initial ruby-install instructions
Don't rely on ruby-install to install ruby dependencies.
Remove some hardcoded ruby-install version information
Remove hardcoded ruby 2.0.0 patch level for PATH
Add note about using --update to avoid hardcoding the ruby patchlevel
TEMP: Use my fork's branch for building

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