As a new user, I want to sign up and create my user account so that I can login to my personal account.

[lguebeli]

Acceptance Criteria:

• After successful registration, users are automatically navigated to the dashboard page

• Users can not register with a username that is already taken

• Users can logout and login with their chosen credentials.

• [x] sopra-fs24-group-29/rapidhabit-client#33

• [x] sopra-fs24-group-29/rapidhabit-client#34

• [x] sopra-fs24-group-29/rapidhabit-client#32

• [x] sopra-fs24-group-29/rapidhabit-client#31

• [x] sopra-fs24-group-29/rapidhabit-server#16

• [x] sopra-fs24-group-29/rapidhabit-server#55

• [x] sopra-fs24-group-29/rapidhabit-server#56