viur create is not functional when there is no project.json

[phorward]

I want to setup a new, clean project. This isn't possible with viur-cli.

$ viur create 
ERROR: project.json not found - please check if you are in the right folder.

It is a contradiction that viur-cli requires a project.json, although the new project is to be created first. This makes no sense at all, and a solution must be worked out so that viur-cli can be used sensibly both with and without project.json.

In general, the project.json should only be read when a project-specific command is executed. For example, viur --help or viur --version is not a command that requires a project, just like viur create.

[phorward]

At the same time, please also integrate clean-base.py into viur create so that it can be removed from the base. Likewise, viur-gcloud-setup.sh is still executed in viur create, although it has already been integrated into cli.