[FAB-6726] move to gradle 4.2.1

Change-Id: I41cb62eeb52b2da9f26a1b36a7cdb362c5980ac9
Signed-off-by: Luis Sanchez <sanchezl@us.ibm.com>

Author: Luis Sanchez

gradle/wrapper/gradle-wrapper.jar

@@ -1,6 +1,5 @@
-#Wed Aug 23 07:28:06 EDT 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.0.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.2.1-bin.zip