This commit takes all backend changes for signup and invite feature. I
was working on these features and removed the generated mutations for
type user along the way.
@ulfgebhardt: The reason why the test case was failing is pretty
obvious. You forgot to create a user that you want to update. If there
is no user to update, then you get an empty response.
@ulfgebhardt: I moved the spec also in the right directory. You're
testing resolvers, so that's where I moved the `.spec` file.
@ulfgebhardt @mattwr18 @tirokk
Here's how I imagined the data validation middleware. If we roll our own
input validations I would suggest to put them all in one place.
@ulfgebhardt this commit is a great example of how tests can speed you
up: Since I can rely on existing tests, I don't have to check the validations
manually. With tests you can refactor with confidence! 👍
