Fixed #708: Added 'use strict' and replaced var with let/const in fs.appendFile.spec.js (#713)
Fixed #708: Added 'use strict' and replaced var with let/const in fs.appendFile.spec.js (#713)

* Add files via upload

* Add files via upload

* Revert "Add files via upload"

This reverts commit 214977d8bff90f089e06d20667628adf046f0ecb.

* Update fs.appendFile.spec.js

* s

* Revert "s"

This reverts commit 8aa5cbbbd640d415ba9c39491beb926ab5caccc5.

* Changed all `let` to `const`

As informed, all variables will not change at all in this file, therefore all `let` declarations have been changed to `const`

humphd/filer,filerjs/filer,humphd/filer,filerjs/filer