Fix webpack building loop

lib/build.js

@@ -16,6 +16,7 @@ import serverWebpackConfig from './webpack/server.config.js'
 const debug = require('debug')('nuxt:build')
 const remove = pify(fs.remove)
 const readFile = pify(fs.readFile)
+const utimes = pify(fs.utimes)
 const writeFile = pify(fs.writeFile)
 const mkdirp = pify(fs.mkdirp)
 const glob = pify(require('glob'))
@@ -243,7 +244,13 @@ function * generateRoutesAndFiles () {
         }
       })
       const content = template(templateVars)
-      return writeFile(r(this.dir, '.nuxt', file), content, 'utf8')
+      const path = r(this.dir, '.nuxt', file)
+      return writeFile(path, content, 'utf8')
+      .then(() => {
+        // Fix webpack loop (https://github.com/webpack/watchpack/issues/25#issuecomment-287789288)
+        const dateFS = Date.now() / 1000 - 10
+        return utimes(path, dateFS, dateFS)
+      })
     })
   })
   yield moveTemplates