Change shebang to bash for proper color output

When running ```./oodt start``` using the ```#!/bin/sh``` shebang I get,
![screen shot using sh](https://cloud.githubusercontent.com/assets/2089880/4964340/b2651816-670d-11e4-97e5-43fc1ced0bde.png)
When running it with the ```#!/usr/bin/env bash``` shebang I get,
![screen shot using bash](https://cloud.githubusercontent.com/assets/2089880/4964342/cc2582f4-670d-11e4-8615-8399bb9b5862.png)