fixed #15 message broker is now rendered

Author: aheil

EIP_Elements.puml

@@ -230,7 +230,7 @@ _alias -- _rulebase
 /'  EIP Pattern: Message Broker
     Link: https://www.enterpriseintegrationpatterns.com/patterns/messaging/MessageBroker.html
 '/
-!define MessageBroker(_alias) rectangle as _alias <<message broker>>
+!define MessageBroker(_alias) rectangle " " as _alias <<message broker>>
 !define MessageBroker(_alias, _label) rectangle "_label" as _alias <<message broker>>
 
 /'  ########################################################

dist/EIP-PlantUML.puml

@@ -1,4 +1,4 @@
-' Autogenerated Tuesday, July 9, 2019 9:29:36 PM
+' Autogenerated Tuesday, July 9, 2019 9:38:51 PM
 
 sprite $aggregator [100x65/16z] {
 xTX50iCm34HHcTcw_sdBh4r9nVdxv8LZcrX6pqxkyKCC631Wm801GqO8VTfpnRAdlnzowriDnybe6ucPHpAgHkHD8nfLOrUFHia8l6l7w1exnZt5YBcKMblh
@@ -696,7 +696,7 @@ _alias -- _rulebase
 /'  EIP Pattern: Message Broker
     Link: https://www.enterpriseintegrationpatterns.com/patterns/messaging/MessageBroker.html
 '/
-!define MessageBroker(_alias) rectangle as _alias <<message broker>>
+!define MessageBroker(_alias) rectangle " " as _alias <<message broker>>
 !define MessageBroker(_alias, _label) rectangle "_label" as _alias <<message broker>>
 
 /'  ########################################################