Unskip tests (#516)

* Unskip tests

* fix fn output for errors

* Change Error model and add fn routes call return on error

fn/routes.go

@@ -260,6 +260,7 @@ func callfn(u string, content io.Reader, output io.Writer, method string, env []
 	}
 
 	io.Copy(output, resp.Body)
+
 	return nil
 }