(maint) Version redhat configs and add others
(maint) Use Net::HTTP instead of curl querying downstream job

Remove the external dependency on curl.
(maint) Move the Rake ci namespace into its own tasks file

Cleans up the base Rakefile by extracting out the ci tasks into
tasks/ci.rake.
(maint) Use rake's cp/mv helpers
(maint) Clean up generation of preserved_configs

Previous implementation was a nasty mix of regex grepping and
templating.  This change parses the initial YAML config, extracts
hostnames from the logs and assembles a hash to be dumped via YAML to
the final preserved_configs.yaml file.
(maint) Cleanup the beaker_test method

Avoids potential shell expansion issues in the arguments we are passing
off to Beaker.  Also ensures copying the hosts_file if present, but
generates a preserved_config.yaml only if preserve-hosts was set.
Previously we were only copying hosts_file when preserve-hosts was set.