Fix tests on node 12

Author: BenSurgisonGDS

run-tasks.js

@@ -1,4 +1,5 @@
 const colour = require('nodemon/lib/utils/colour')
+const del = require('del')
 
 function runTasks () {
   clean()
@@ -20,9 +21,7 @@ function generateAssets () {
 
 function clean () {
   // doesn't clean extensions.scss, should it?
-  const fs = require('fs')
-  fs.rmSync('public', { recursive: true, force: true })
-  fs.rmSync('.port.tmp', { force: true })
+  del.sync(['public/**', '.port.tmp'])
 }
 
 function sassExtensions () {