[maven-release-plugin] prepare release joni-2.2.6

Author: headius

pom.xml

@@ -4,7 +4,7 @@
   <groupId>org.jruby.joni</groupId>
   <artifactId>joni</artifactId>
   <packaging>jar</packaging>
-  <version>2.2.6-SNAPSHOT</version>
+  <version>2.2.6</version>
   <name>Joni</name>
   <description>
     Java port of Oniguruma: http://www.geocities.jp/kosako3/oniguruma