UserService userList not safe

[janwytze]

The userList in the UserService is not safe, it is a Map with username and password as key(username:password).

Example: username: example@example.nl password: passw:ord Result: example@example.nl:passw:ord

username: example@example.nl:passw password: ord Result: example@example.nl:passw:ord

The result are the same!
Of course you still have to know the password of the user, so it won't result in users getting hacked.
It can be solved by using a different key(or none) or validating the username better.

[janwytze]

Not the nicest solution, but we could just use another splitting character:
https://stackoverflow.com/a/1879904/2735398

[janwytze]

Solved in #38