Add the first test

Implemented a basic test around exporting a png.
More can follow but at least something to build off of.

.travis.yml

+language: node_js
+node_js:
+  - "0.11"
+  - "0.10"
+  - "0.8"
\ No newline at end of file

package.json

@@ -9,8 +9,12 @@
     "rsvp": "~ 3.0.6",
     "lodash": "~ 2.4"
   },
+  "test": "mocha test",
   "devDependencies": {
     "coffeeify": "~ 0.6.0",
-    "browserify": "~ 3.46.0"
+    "browserify": "~ 3.46.0",
+    "mocha": "~ 1.18.2",
+    "should": "~ 3.3.1",
+    "rimraf": "~ 2.2.8"
   }
 }

test/mocha.opts

+--reporter spec
+--compilers coffee:coffee-script/register
\ No newline at end of file

test/png_exporting.coffee

+PSD           = require '../'
+fs            = require 'fs'
+rimraf        = require 'rimraf'
+path          = require 'path'
+should        = require 'should'
+outputPath    = path.resolve(__dirname, "output")
+fixturesPath  = path.resolve(__dirname, "fixtures")
+
+describe "exporting from a PSD", ->
+  beforeEach (done) ->
+    fs.mkdir outputPath, done
+
+  afterEach (done) ->
+    rimraf outputPath, done
+
+  it "should export a png", (done) ->
+    psdPath       = path.resolve(__dirname, "../", "examples/images/example.psd")
+    filePath      = path.join(outputPath, "out.png")
+    expectedPath  = path.join(fixturesPath, "out.png")
+
+    PSD.open(psdPath)
+    .then (psd) ->
+      psd.image.saveAsPng filePath
+    .then ->
+      fs.statSync(filePath).size
+      .should
+      .eql(fs.statSync(expectedPath).size)
+    .then -> done()
+    .catch done
+