Bug in Checking Key in User Class

[douglasgreen]

There's a bug in the constructor of the User class on User.php line 47:

https://github.com/HansAdema/jsconnect-php/blob/168018a88632bd573eb4fc73aa0b52ba77b92eec/src/User.php#L47

'key' should be $key. It isn't actually checking or setting properties when it is 'key'.

[jinjie]

#1 Fixes this