class Lono::Seed::Configs

This is an optional class is used by `lono seed [blueprint]` to create starter configs. Example files that get created:

configs/BLUEPRINT/params/LONO_ENV.txt
configs/BLUEPRINT/variables/LONO_ENV.rb

The `Lono::Seed::Configs` class should implement:

setup: Hook to perform logic at the beginning. A good place to create IAM service roles.
variables: Template for generated variables file. Contents of what gets created at
  configs/[blueprint]/variables/development.rb

Note: There is no need to define a params method. Lono is able to generate a params config starter file by evaluating the template defintion.