Register a user

To register a user you can either send information about the user, or create a new anonymous user without providing any data. Usually you send information about a user when he's logging into the app or registering - that's when the user passes some data in forms - but before that you might want to create a new user just to gather information about user's events and screen views.
Registering anonymous user
To register anonymous user use ping() method - it will create a user if no attributes were set before.
```
UserSDK.default?.ping()
```
Set standard and custom attributes
You can add any number of custom customer attributes, or use predefined standard attributes
```
UserSDK.default?.setUserData([
   UserSDK.UserDataKey.firstName : "Test",
   UserSDK.UserDataKey.lastName : "User",
   UserSDK.UserDataKey.email : "test@user.com",
   UserSDK.UserDataKey.phone : "+1222333444",
   UserSDK.UserDataKey.userId : "yourcustomerid"
])

UserSDK.default?.setCustomUserData([
   "custom attribute name" : "custom attribute value"
])
```
Logout
To logout and clear all user-related resources within SDK, invoke:
```
UserSDK.default?.logout()
```