solid.js auth create-token prompt "Do you want to create an authentication token for ...": override wanted

[mvanbrab]

For automation purposes (usage in an unattended script) a -y option is needed to avoid the prompt.
Probably related to #37.

[mvanbrab]

Found a workaround for this one:
before calling, do node bin/solid.js auth clear. This will clear the currently active WebID and the prompt will disappear.