Per project parameter resolvers

[stevehodgkiss]

StackMaster doesn't contain many parameter resolvers. It would be useful if there were a way to quickly build them inside of a project before deciding whether to submit a PR to StackMaster with the resolver.

Proposal:

Add a new directory named parameters_resolvers. All ruby files in that directory would be loaded. A resolver could be defined like this:

StackMaster.resolver(:rds_cluster) do # defines a class and hooks things up under the hood
  def call(value)
    value.reverse
  end
end

[gstamp]

Nice idea.