MintGate

[INFLOWMusic]

Await Jennifer's PR on react hook and server code updates then :

• [x] test Mintgate API get mintgated urls onClick handler in Artist Mangement page.
• [x] create post route, controller and update artist schema
• [x] authorize('artist') on v1/artist.routes.js '/updatemintegateurls'

Link buttons on component/Artist.js to token gated URLs