Paris: credit other organizers

Signed-off-by: Holger Levsen <holger@layer-acht.org>

_events/paris2018.html

@@ -125,7 +125,7 @@ event_summary: A three-day workshop to continue and grow the Reproducible Builds
   <div class="eight columns text">
     <a href="https://aspirationtech.org/"><img src="{{ "/images/logos/aspirationtech.jpg" | prepend: site.baseurl }}" alt="Aspiration" style="margin: 20px;"/></a>
     &amp;
-    <a href="mailto:holger@layer-acht.org">Holger</a>
+    Holger, Nicolas, Vagrant, Chris and Mattia
   </div>
 </div>
 <div class="row">