Install instructions

[slick2]

@afk11 instructions on the README.md

npm install -g gulp
git clone https://github.com/blocktrail/blocktrail-webwallet.git
cd  blocktrail-webwallet
npm install
git submodule update --init --recursive # for translations package
cp appconfig.example.json appconfig.json
gulp

[slick2]

also please include the minimum node.js version to run, i've tried node version 0.10 upto 4.0, i've got it working on 7.0

[afk11]

I'll update the readme with that, thanks! I'll have to look at the minimum, I usually use v0.12.15 or so, but worth mentioning.