change Gradle to 6.1.1

Signed-off-by: tobiasKaminsky <tobias@kaminsky.me>

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Wed Aug 21 07:03:37 CEST 2019
+#Fri May 29 07:39:21 CEST 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.4-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip