Add upgradable scopes to customer token creation (#379)

Author: GermanSmoliar

types/customerToken.ts

@@ -52,6 +52,11 @@ export interface CreateTokenRequest {
          */
         scope: string
 
+        /**
+         * list of Upgradable scopes separated by spaces.
+         */
+        upgradableScope?: string
+
         /**
          * Received as a response from Create Customer Token Verification.
          * Required if scope includes a scope which require two-factor authentication.