provider=none forces not using a token.

src/service.cr

@@ -91,6 +91,8 @@ commands.push "add", "Adds a service to an environment." do |context, args|
 
 			if provider.nil?
 				provider = service.get_default_provider token.token
+			elsif provider == "none"
+				provider = nil
 			end
 
 			next if provider.nil? && token.optional