Bump used gerrit API and hooks-its to version 2.8-SNAPSHOT

Change-Id: I8fc2bfa643bf5b49a159af08f8fc8c4a38b3b773
diff --git a/pom.xml b/pom.xml
index e8ad831..0741b55 100644
--- a/pom.xml
+++ b/pom.xml
@@ -21,7 +21,7 @@
 
   <groupId>com.googlesource.gerrit.plugins.bugzilla</groupId>
   <artifactId>hooks-bugzilla</artifactId>
-  <version>2.7-SNAPSHOT</version>
+  <version>2.8-SNAPSHOT</version>
 
   <name>Gerrit - Bugzilla support</name>