Update versions in pom's to start Gerrit 2.6 development

Change-Id: I4fb8cb41250c5b640a8d9e47caf97dc4670ff428
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

gerrit-antlr/pom.xml

diff --git a/gerrit-antlr/pom.xml b/gerrit-antlr/pom.xml
index 34cb46f..314d8d2 100644
--- a/gerrit-antlr/pom.xml
+++ b/gerrit-antlr/pom.xml
@@ -22,7 +22,7 @@
   <parent>
     <groupId>com.google.gerrit</groupId>
     <artifactId>gerrit-parent</artifactId>
-    <version>2.5-SNAPSHOT</version>
+    <version>2.6-SNAPSHOT</version>
   </parent>
 
   <artifactId>gerrit-antlr</artifactId>