Update parent version to 2.8-SNAPSHOT

Change-Id: I75cc94e5d3d6459815f05785f515cb71729bb08e
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

pom.xml

diff --git a/pom.xml b/pom.xml
index e863808..d1e8b6e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>com.googlesource.gerrit.plugins.its</groupId>
     <artifactId>hooks-its-parent</artifactId>
-    <version>2.6-SNAPSHOT</version>
+    <version>2.8-SNAPSHOT</version>
   </parent>
   <artifactId>hooks-rtc</artifactId>
   <name>Gerrit Code Review - IBM Rational Team Concert support</name>