Roll version number up to 5.3.0, prior to generating the release

git-svn-id: https://svn.apache.org/repos/asf/tapestry/tapestry5/trunk@1136262 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/build.gradle b/build.gradle
index c0b9158..820fddb 100644
--- a/build.gradle
+++ b/build.gradle
@@ -6,7 +6,7 @@
 easymockVersion = '3.0'
 servletAPIVersion = '2.4'
 
-version = '5.3.0-SNAPSHOT'
+version = '5.3.0'
 
 doSign = !project.hasProperty('noSign') && project.hasProperty("signing.keyId")