Modify path to mocha
Apply parent constructor of Driver

Node 0.9 requires this.
Upgrade zombie version to 2.0.0

`browser.window` is refreshed when page loaded from Zombie 2.
And then `postMessage` disabled is cleared.

So I disable `postMessage` after page loaded.
Remove unused module
Add missing semicolon
Export at top level
Emit original error
Add test about test result
Emit error when test not run
Extract function for creating error
Node 0.9 is not supported
Bump version to 0.2.0