Script to set up sheep dev environment

[shardros]

People feel like it's hard to work out how to develop sheep because they don't know how to set up the dev environment.

We should have a script to install:

• Node
• Nvm
• Set the node version to the node version in package.json
• Dependencies

[shardros]

Thinking about it running npm run start should try and start mock shephered if it isnt' already started and then if it isn't already installed it should install it.