Simplify npm scripts and travs setup

.jshintignore

@@ -1,2 +1,3 @@
 node_modules
 testdata
+coverage

.travis.yml

@@ -1,10 +1,31 @@
+sudo: required
+services:
+  - docker
 language: node_js
 node_js:
-  - "0.10"
-  - "0.12"
-  - "iojs-v2.3.1"
-before_install: "sudo apt-get update && sudo apt-get install -y libcairo2-dev libjpeg8-dev libgif-dev optipng pngcrush pngquant libpango1.0-dev"
+  - '4'
+  - '3'
+  - '2'
+  - '1'
+  - '0.12'
+  - '0.10'
+cache:
+  directories:
+    - node_modules
+addons:
+  apt:
+    packages:
+      - gcc-4.8
+      - g++-4.8
+      - libcairo2-dev
+      - libjpeg8-dev
+      - libgif-dev
+      - libpango1.0-dev
+
+env: CXX="g++-4.8" CC="gcc-4.8"
+
 script: "npm run-script travis"
+after_success: "<coverage/lcov.info ./node_modules/coveralls/bin/coveralls.js"
 
 notifications:
   webhooks:

package.json

@@ -44,8 +44,8 @@
   "scripts": {
     "lint": "jshint .",
     "test": "npm run lint && mocha",
-    "travis": "npm run lint && NODE_ENV=development ./node_modules/.bin/istanbul cover ./node_modules/mocha/bin/_mocha -- --reporter dot && cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js",
-    "coverage": "NODE_ENV=development ./node_modules/.bin/istanbul cover ./node_modules/mocha/bin/_mocha -- --reporter dot"
+    "coverage": "istanbul cover _mocha",
+    "travis": "npm run lint && npm run coverage"
   },
   "main": "lib/spriteBackgroundImages.js"
 }