Prepare for release 2.4.0.
diff --git a/pom.xml b/pom.xml
index 4387356..cccc466 100644
--- a/pom.xml
+++ b/pom.xml
@@ -26,7 +26,7 @@
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <artifactId>commons-dbcp2</artifactId>
-  <version>2.4.0-SNAPSHOT</version>
+  <version>2.4.0</version>
   <name>Apache Commons DBCP</name>
 
   <inceptionYear>2001</inceptionYear>