travis: don't send email notifications

I never received any email from travis and actually don't want to. Thus, I'm
removing my email address from the notification list.

Signed-off-by: David Wagner <[email protected]>

Author: dawagner

.travis.yml

@@ -63,7 +63,5 @@ after_success:
           --gcov-options '\--long-file-names --preserve-paths'
 
 notifications:
-  email:
-    - [email protected]
   irc:
     - "chat.freenode.net#parameter-framework"