update build and test scripts (mgechev#143)

Author: krzysztof-grzybek

.travis.yml

@@ -1,6 +1,4 @@
 language: node_js
 node_js:
   - "8"
-before_script:
-  - npm install -g gulp
-script: gulp build
+script: npm run build

package.json

@@ -16,6 +16,7 @@
     "live-server": "^1.2.0"
   },
   "scripts": {
+    "build": "gulp build",
     "test": "gulp test",
     "deploy": "npm run doc:build && gh-pages -d dist -b gh-pages",
     "doc": "npm run doc:build && npm run doc:view",

readme.md

@@ -34,7 +34,7 @@ Just run `npm run doc` again.
 Call:
 
 ```bash
-gulp test
+npm run test
 ```
 
 and all `*.spec.js` files will be executed.
@@ -57,7 +57,7 @@ Make sure you're editor makes validations according to the `.jshintrc` in the ro
 Before pushing to the repository run:
 
 ```bash
-gulp build
+npm run build
 ```
 
 If the build is not successful fix your code in order the tests and jshint validation to run successfully and after that