Update travis config and some scripts

Author: Carlos Lancha

.travis.yml

@@ -1,7 +1,12 @@
+before_install:
+  - nvm install 8
+
+install:
+  - npm install
+
 language: node_js
-node_js:
-  - "node"
-  - "6"
-script:
-  - npm test
+
+script: 
+  - npm run compile
   - npm run lint
+  - npm run jest

package.json

@@ -11,10 +11,11 @@
     "lib"
   ],
   "scripts": {
-    "lint": "tslint src/**/*.ts",
-    "test": "npm run compile && jest",
     "compile": "tsc",
-    "prepublish": "npm run compile"
+    "jest": "jest",
+    "lint": "tslint src/**/*.ts",
+    "prepublish": "npm run compile",
+    "test": "npm run compile && jest"
   },
   "jest": {
     "moduleFileExtensions": [