add support for 'mysql_clear_password' auth plugin

Author: nmggithub

lib/protocol/Auth.js

@@ -8,6 +8,8 @@ function auth(name, data, options) {
   switch (name) {
     case 'mysql_native_password':
       return Auth.token(options.password, data.slice(0, 20));
+    case 'mysql_clear_password':
+      return Buffer.from(options.password);
     default:
       return undefined;
   }