fix(package): update i18next-xhr-backend to version 3.1.1

Closes #26

Author: greenkeeper[bot]

package.json

@@ -49,7 +49,7 @@
     "homepage": "https://github.com/koreezgames/phaser3-i18n-plugin#readme",
     "dependencies": {
         "i18next": "^15.0.2",
-        "i18next-xhr-backend": "^2.0.0"
+        "i18next-xhr-backend": "^3.1.1"
     },
     "peerDependencies": {
         "phaser": "^3.12.0"