message: Add snapshot as org info field saved in auth file
diff: * @property {string} privateKey
  * @property {string} refreshToken
  * @property {string} scratchAdminUsername
  + * @property {string} snapshot
  * @property {string} userId
  * @property {string} username
  * @property {string} usernames
  @@ -83,6 +84,7 @@ export interface AuthFields {
  privateKey?: string;
  refreshToken?: string;
  scratchAdminUsername?: string;
  + snapshot?: string;
  userId?: string;
  username?: string;
  usernames?: string[];
  