def load_params(opts = {})
      Dotenv.load if opts[:use_dotenv]
      manifest.each do |p|
        env_name = p[:name].to_s
        if p[:const]
          # const
          @params[p[:name]] = p[:default]
        elsif p[:required]
          # required configurable
          @params[p[:name]] = ENV[env_name] if ENV.key?(env_name)
        else
          # optional configurable
          @params[p[:name]] = ENV.key?(env_name) ? ENV[env_name] : p[:default]
        end
      end
      @params
    end
def load_params(opts = {})
      Dotenv.load if opts[:use_dotenv]
      manifest.each do |p|
        env_name = p[:name].to_s
        if p[:const]
          # const
          @params[p[:name]] = p[:default]
        elsif p[:required]
          # required configurable
          @params[p[:name]] = ENV[env_name] if ENV.key?(env_name)
        else
          # optional configurable
          @params[p[:name]] = ENV.key?(env_name) ? ENV[env_name] : p[:default]
        end
      end
      @params
    end
Reads parameters from the ENV according to the current manifest