Revert build to Gradle 2.13

Issue: SPR-14362

Author: sbrannen

build.gradle

@@ -1367,7 +1367,7 @@ configure(rootProject) {
 
 	task wrapper(type: Wrapper) {
 		description = "Generates gradlew[.bat] scripts"
-		gradleVersion = "2.14"
+		gradleVersion = "2.13"
 
 		doLast() {
 			def gradleOpts = "-XX:MaxMetaspaceSize=1024m -Xmx1024m"

gradle/wrapper/gradle-wrapper.jar

@@ -1,6 +1,6 @@
-#Tue Jun 14 17:29:02 CEST 2016
+#Wed Jun 15 12:59:30 CEST 2016
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.14-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.13-bin.zip