Fixed dev deps in package.json and updated Makefile and README.

@tblobaum Noted that ```package.json``` included ```sequence``` as a dependency when it really is a dev-dependency as ```mocha```. On production, neither will be installed, now.

In addition, I prefer to install all modules locally so now ```mocha``` is in ```node_modules``` and the ```Makefile``` is correctly launching this instance.

Tests can be executed directly by:

```javascript
npm install
npm test
```