Set all permissions to 0644 vs a mixture

This appeared to prevent the provider's secret code from
creating files in its working directory. The patch makes all
code use the same permission.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

cmd/up.go

@@ -193,7 +193,7 @@ func makeFile(filePath, fileContents string) error {
 		return nil
 	} else if os.IsNotExist(err) {
 		log.Printf("Writing to: %q\n", filePath)
-		return ioutil.WriteFile(filePath, []byte(fileContents), 0644)
+		return ioutil.WriteFile(filePath, []byte(fileContents), workingDirectoryPermission)
 	} else {
 		return err
 	}