Add GraphViz dependency install to travis config

Mark Robinson · Mark Robinson · commit 0917590d13aa · 2017-03-18T14:40:02.000Z
diff --git a/.travis.yml b/.travis.yml
@@ -4,3 +4,7 @@ dist: trusty
 language: java
 
 services: mongodb
+
+before_install:
+  - sudo apt-get -qq update
+  - sudo apt-get install graphviz
