Limited CI builds to Node LTS versions

Author: JamesMessinger

.travis.yml

@@ -14,18 +14,16 @@ addons:
 matrix:
   include:
     # Browsers
-    - node_js: 8
+    - node_js: 10
       env: KARMA=true
 
-    - node_js: 8
+    - node_js: 10
       env: KARMA=true SAUCE=true
 
     # Node
-    - node_js: 4
-    - node_js: 5
     - node_js: 6
-    - node_js: 7
     - node_js: 8
+    - node_js: 10
 
 before_script:
   # Setup a virtual display for browser testing