Set domain command

[liorkesos]

We need to get the syntax for this (and the httpopen command #6) right
Basically the command is supposed to change the value in {{appdir}/.env and restart the traefik proxy (to get it to take effect
TODO: Review the SSL state in the end of this command....

[niryariv]

@liorkesos are we setting URL or just domain here?

[niryariv]

Per discussion w/ @liorkesos changing this to set domain instead of URL - we'll be asking the user for the domain only

[billylkc]

Implemented in dev, should be available in 0.1.6

[niryariv]

@niryariv review

[niryariv]

@liorkesos need your advice on how to test