Upgrade SF to snapshot

Author: garyrussell

build.gradle

@@ -82,7 +82,7 @@ subprojects { subproject ->
 		mockitoVersion = '2.22.0'
 		scalaVersion = '2.11'
 		springRetryVersion = '1.2.2.RELEASE'
-		springVersion = '5.1.0.RELEASE'
+		springVersion = '5.1.2.BUILD-SNAPSHOT'
 		springDataCommonsVersion = '2.1.0.RELEASE'
 
 		idPrefix = 'kafka'