def staging_versions
      possible_versions = [1, 2]
      @versions ||= []
      possible_versions.each do |version|
        begin
          @conn.get "/api/v#{version}/stage"
          @versions.push version
        rescue SFRest::InvalidResponse
          nil
        end
      end
      @versions
    end
def staging_versions
      possible_versions = [1, 2]
      @versions ||= []
      possible_versions.each do |version|
        begin
          @conn.get "/api/v#{version}/stage"
          @versions.push version
        rescue SFRest::InvalidResponse
          nil
        end
      end
      @versions
    end
determine what version are available for staging
 @return [Array] Array of available api endpoints