Adopt the Gradle versions for test as per @ysb33r's recommendation

Author: rtyler

build.gradle

@@ -73,9 +73,9 @@ subprojects {
         gradleTest {
             // https://github.com/jruby-gradle/jruby-gradle-plugin/issues/346
             if (JavaVersion.current().java11) {
-                versions '5.0'
+                versions '5.0', '5.4.1'
             } else {
-                versions '4.2', '4.7', '4.10'
+                versions '4.2', '4.10.2', '5.3.1'
             }
             dependsOn jar
         }