Make the computer assistant multi-user

[arobirosa]

Is your feature request related to a problem? Please describe.
The proof concept can only be used by one user because the server saves the state of the symptoms.

Describe the solution you'd like
To make the diagnose stateless and the client must send the symptoms.

Describe alternatives you've considered
Another alternative is to use HTTP Sessions but this makes testing difficult and it don't scale.

Additional context
None