chore: test on node 10 and 11

Author: digitalsadhu

.travis.yml

@@ -1,5 +1,7 @@
 language: node_js
 node_js:
+  - '11'
+  - '10'
   - '8'
 script:
   - npm test
@@ -12,4 +14,4 @@ after_success:
   - npm run travis-deploy-once "npm run semantic-release"
 branches:
   except:
-    - /^v\d+\.\d+\.\d+$/
+    - /^v\d+\.\d+\.\d+$/