Added package caching and fixed 'main' in package.json.

.travis.yml

@@ -1,5 +1,8 @@
 language: node_js
 node_js:
   - "0.10"
+cache:
+  directories:
+    - node_modules
 before_script:
-  - npm install -g flex-sdk
+  - npm install flex-sdk

package.json

@@ -3,7 +3,7 @@
   "description": "Open source version of the Scratch 2.0 project editor.",
   "version": "1.0.0",
   "homepage": "http://scratch.mit.edu/",
-  "main": "./lib/serious-calculations",
+  "main": "scratch-flash",
   "license": "GPL-2.0",
   "repository": {
     "type": "git",