Bump version to 2.2.0

Change-Id: I312a7bdc61d4ffaa7d890b82c4530ab5754e9dee
diff --git a/pom.xml b/pom.xml
index d701219..20dcd4c 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>groupId</groupId>
     <artifactId>totalngrams</artifactId>
-    <version>2.1.0</version>
+    <version>2.2.0</version>
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>