Added test command to Travis CI

.travis.yml

@@ -1,12 +1,13 @@
 language: node_js
 
 node_js:
-  - "8"
+  - "node"
 
 before_install:
   - cp ./server/config.example.js ./server/config.js
   - cp ./client/config.example.js ./client/config.js
 
 script:
-  - npm run lint:nofix
-  - npm run build
+  - yarn run lint:nofix
+  - yarn test
+  - yarn build