Set release version to 3.1.0.RC1

build.gradle

@@ -1,7 +1,7 @@
 apply plugin: 'base'
 
 allprojects {
-    version = '3.1.0.CI-SNAPSHOT'
+    version = '3.1.0.RC1'
     releaseBuild = version.endsWith('RELEASE')
     snapshotBuild = version.endsWith('SNAPSHOT')