Release 5.2.0.RC1

gradle.properties

@@ -1,5 +1,5 @@
 aspectjVersion=1.9.3
 gaeVersion=1.9.76
 springBootVersion=2.2.0.M5
-version=5.2.0.BUILD-SNAPSHOT
+version=5.2.0.RC1
 org.gradle.jvmargs=-Xmx3g -XX:MaxPermSize=2048m -XX:+HeapDumpOnOutOfMemoryError