Fixes for newer Rubies

[davewongillies]

Two fixes to get fpm-cookery working on newer systems:

• Add xmlrpc as a dependency on systems running ruby 2.4.0 or greater (it was previously in the stdlib but has since been removed, and puppet requires it)
• Monkey patch OpenSSL::SSL::SSLContext with an if block when attempting to set DEFAULT_PARAMS[:ciphers], otherwise puppet will error out with an undefined method error. More info in PUP-7383.

I've tested this out on the following systems with their distro rubies:

• Ubuntu 18.04: ruby 2.5.1p57
• Ubuntu 16.04: ruby 2.3.1p112
• Ubuntu 14.04: ruby 1.9.3p484

[madelaney]

👍

[davewongillies]

Closing this since I'm not really even sure it works anymore.