fix(turbo): warn users that Node v14 is required (#1411)

Author: benjie

.eslintrc.js

@@ -1,4 +1,5 @@
 module.exports = {
+  root: true,
   parser: '@typescript-eslint/parser',
   parserOptions: {
     sourceType: 'module',

isTurbo.js

@@ -1,7 +1,9 @@
 if (process.env.GRAPHILE_TURBO === '1') {
   const major = parseInt(process.version.replace(/\..*$/, ''), 10);
-  if (major < 12) {
-    throw new Error('Turbo mode requires Node v12 or higher');
+  if (major < 14) {
+    throw new Error(
+      'Turbo mode currently requires Node v14 or higher, please upgrade Node.js or remove the GRAPHILE_TURBO environmental variable.',
+    );
   }
   module.exports = true;
 } else {