fix: pin typescript version to 3.5 until we support typescript-eslint 2

Author: haoqunjiang

packages/@vue/cli-plugin-typescript/generator/index.js

@@ -11,7 +11,7 @@ module.exports = (api, {
 
   api.extendPackage({
     devDependencies: {
-      typescript: '^3.4.5'
+      typescript: '~3.5.3'
     }
   })