Merge pull request #178 from web-push-libs/renovate/com.github.johnrengelman.shadow-7.x

Update plugin com.github.johnrengelman.shadow to v7

Author: martijndwars

build.gradle

@@ -1,6 +1,6 @@
 plugins {
     id 'application'
-    id 'com.github.johnrengelman.shadow' version '6.1.0'
+    id 'com.github.johnrengelman.shadow' version '7.1.1'
 
     // Used by release.gradle
     id 'maven-publish'