Improve deploy process

[syrusakbary]

As a user, if I go to a repo with a set app.yaml for which I don't have permissions to push (eg: https://github.com/wasmer-examples/wordpress-wasmer-starter )

Basically, an app.yaml with either [owner & name] or [app_id] (or both). If I don't have permissions to deploy, it should prompt me if I want to deploy to a new app, and if I confirm.. then delete owner, name and app_id and trigger again the deploy process.

Example:

$ git clone https://github.com/wasmer-examples/wordpress-wasmer-starter && cd wordpress-wasmer-starter
$ wasmer deploy
It seems the app {name} ({owner}) doesn't exist, or you don't have permissions for it.
Do you want to deploy this as a new app? (y/n)
# Delete owner, name and app_id from app.yaml
# Trigger the deploy flow again