add cache and formatter (mgechev#748)

* add cache and formatter

* Update .travis.yml

* Update .travis.yml

* Update .travis.yml

Author: Shyam-Chen

.travis.yml

@@ -1,31 +1,38 @@
 language: node_js
 node_js:
-- '4.0'
-- '4.1'
-- '5.1'
+  - 4
+  - stable
+
 sudo: false
-services:
+
 before_install:
-- npm --version
-- export CHROME_BIN=chromium-browser
-- export DISPLAY=:99.0
-- sh -e /etc/init.d/xvfb start
+  - export CHROME_BIN=chromium-browser  # Karma CI
+  - export DISPLAY=:99.0
+
 before_script:
-notifications:
-  email: true
-after_failure: cat /home/travis/build/mgechev/angular2-seed/npm-debug.log
+  - sh -e /etc/init.d/xvfb start
+  # - nohup bash -c webdriver-manager start 2>&1 &  # Protractor CI
+  - sleep 1  # give server time to start
+
+after_failure:
+  - cat /home/travis/build/mgechev/angular2-seed/npm-debug.log
+
 branches:
-  only:
-  - master
+  only: master
+
 notifications:
+  email: true
   webhooks:
-    urls:
-      - https://webhooks.gitter.im/e/565e4b2fed3b96c1b964
+    urls: https://webhooks.gitter.im/e/565e4b2fed3b96c1b964
     on_success: change  # options: [always|never|change] default: always
     on_failure: always  # options: [always|never|change] default: always
     on_start: never     # options: [always|never|change] default: always
+
 env:
   global:
-  # https://github.com/DefinitelyTyped/tsd#tsdrc
-  # Token has no scope (read-only access to public information)
-  - TSD_GITHUB_TOKEN=9b18c72997769f3867ef2ec470e626d39661795d
+    # https://github.com/DefinitelyTyped/tsd#tsdrc
+    # Token has no scope (read-only access to public information)
+    - TSD_GITHUB_TOKEN=9b18c72997769f3867ef2ec470e626d39661795d
+
+cache:
+  directories: node_modules