Update travis

.travis.yml

@@ -9,10 +9,10 @@ jobs:
       node_js:
         - 12
       name: "Lint src and check docs"
-      before_install:
+      script:
         - cd tools
         - git clone --depth=1 https://github.com/wenzhixin/bootstrap-table-examples
-      script: npm run pre-commit
+        - npm run pre-commit
       if: branch != master AND type = pull_request
 
     - stage: deploy