move linting into tests so jobs fail quicker

Author: e-e-e

.travis.yml

@@ -6,12 +6,10 @@ node_js:
   - 9
   - 10
 script:
+  - npm run lint
   - npm run test
 jobs:
   include:
-    - stage: lint
-      node_js: 8
-      script: npm run lint
     - stage: coverage
       node_js: 8
       script: npm run travis