Added some AdServers/DSP Domains (closes #155)

Author: Oliver Paessens

resources/referers.yml

@@ -3759,10 +3759,24 @@ paid:
     domains:
       - adform.net
 
+  Adition:
+    domains:
+      - adition.com
+
+  AdNET:
+    domains:
+      - adnet.de
+
   AdRoll:
     domains:
       - adroll.com
 
+  AdSpirit:
+    domains:
+      - adspirit.de
+      - rtbcity.com
+      - plusperformance.com
+
   AppNexus:
     domains:
       - ib.adnxs.com