Updated bash shebang on shell scripts for portability

This fixes #2781



	modified:   example-build.sh

	modified:   install.sh

example-build.sh

-#!/bin/bash
+#!/usr/bin/env bash
+
 export METEOR_SETTINGS=$(cat settings.json)
 meteor add rocketchat:hubot meteorhacks:kadira
 meteor build --server https://demo.rocket.chat --directory /var/www/rocket.chat

install.sh

-#!/bin/bash
+#!/usr/bin/env bash
 
 ROOTPATH=/var/www/rocket.chat
 PM2FILE=pm2.json