Mark the version up to 2.2.0 for this milestone's development

Author: R. Tyler Croy

build.gradle

@@ -10,7 +10,7 @@ buildscript {
 }
 
 group = 'com.lookout'
-version = '2.1.0'
+version = '2.2.0'
 
 if (System.env.RELEASE != '1') {
     version = "${version}-SNAPSHOT"