Added overriding defaults with environment variables

[ulayera]

How to test it:

export PROJECT_NAME=Env Var Test
yo keystone auto
"project will be created at env-var-test/"

Why this is useful:

docker create -e PROJECT_NAME="My Keystone Page" someuser/keystone:latest

[ulayera]

@Industrial ?

[Industrial]

Ehm, yes @ulayera ?

[ulayera]

Hi, wanted to add this to master yesterday but found a workaround.
Now i'm just creating the docker image with yo keystone auto and mounting the entire dir to the host folder. This way i can edit everything directly in the host.
Thanks for answering anyway.