Missing steps in Quick Start Guide

[leesharma]

This issue comes from #94 (Problems 1 & 2)

System: Fedora 23

Current Behavior

The Quick Start Guide in the README describes some of the required dependencies of the project:

By the end of this section, you should have the project and dependencies installed on your local system. For information on how to contribute, see Contributing.

You need:

• Ruby 2.3
• Rails 4.2.x
• Postgres 9.5 (May be changed by team later)
• PhantomJS (brew install phantomjs on macOS or read instructions)

Basically you need Git, Ruby and Rails. If you have Git, Ruby and Postgres in some version or another you're probably set. But:

• If you're working on a virgin Windows machine, you're best off going with the RailsInstaller at http://railsinstaller.org.
• If you have a virgin Mac OSX machine, just follow the directions in https://gorails.com/setup/osx/10.11-el-capitan.

However, note that this doesn't mention a Javascript runtime–required for Rails development–and that we only include links/advice for OS X and Windows.

Desired Behavior

1) We should be clear that a javascript runtime (preferably Node) is required for development.

2) Ideally, we should also include some links/assistance on how to install the project dependencies (postgres, node, ruby, rails, etc) for people with Linux machines.

I think README.md is the best place for this since we have no setup instructions in the wiki.

[JeanJoeris]

@danbroadbent and I are happy to add some documentation about needing node installed along with some resources for installation.