Error tests

	modified:   t/error.t
	new file:   t/inc/Testing/Error.pm
finish up porting test suite to Test::Roo

	new file:   t/inc/Testing/Request.pm
	new file:   t/inc/Testing/Request/Current.pm
	new file:   t/inc/Testing/Request/Forecast.pm
	modified:   t/openweathermap.t
	modified:   t/request/current.t
	modified:   t/request/forecast.t