refactor: move fs util into template.js

src/util/fs.js

@@ -1,15 +0,0 @@
-import fs from 'fs'
-
-export function readFileAsync (filepath) {
-  return new Promise(function (resolve, reject) {
-    fs.readFile(filepath, 'utf8', function (err, content) {
-      err ? reject(err) : resolve(content)
-    })
-  })
-};
-
-export function statFileAsync (path) {
-  return new Promise(function (resolve, reject) {
-    fs.stat(path, (err, stat) => err ? reject(err) : resolve(stat))
-  })
-};