Bump version to 1.6-SNAPSHOT

Change-Id: Ie150e54ae10941c68de2a43724dd8dfdd9462d57
diff --git a/pom.xml b/pom.xml
index 2d8bb0f..d0d1138 100644
--- a/pom.xml
+++ b/pom.xml
@@ -21,7 +21,7 @@
   <groupId>gwtorm</groupId>
   <artifactId>gwtorm</artifactId>
   <packaging>jar</packaging>
-  <version>1.5</version>
+  <version>1.6-SNAPSHOT</version>
   <name>gwtorm</name>
   <description>Tiny ORM</description>
   <url>https://gerrit.googlesource.com/gwtorm</url>