'special_kwargs'

'special_kwargs' method now takes no arguments. Any contextual values
should be gotten from the view callable 'self' object.
'self.request'

'request' object is attached to 'self' during '__call__'. 'request' is
no longer passed directly to 'view_call' as an argument.
'authenticate' tests

Add tests for 'BaseViewCallable' 'authenticate' method. This method is
overridden by the user to implement authentication.
'authenticate' method

Implement 'BaseViewCallable.authenticate' method.