Update POM version for Apache release 2.9.0

Author: garydgregory

pom.xml

@@ -24,7 +24,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>commons-io</groupId>
   <artifactId>commons-io</artifactId>
-  <version>2.9.0-SNAPSHOT</version>
+  <version>2.9.0</version>
   <name>Apache Commons IO</name>
 
   <inceptionYear>2002</inceptionYear>