Move update post scripts into one script called post

Simplify the update shell script by combining the Node.js post scripts
into one mega script.

We also move the final message from update script to very end.

lib/_update/post.js

@@ -0,0 +1,5 @@
+const { updateJavascripts } = require('./update-javascripts')
+const { updateScss } = require('./update-scss')
+
+updateJavascripts()
+updateScss()

lib/_update/update-javascripts.js

@@ -25,10 +25,5 @@ async function updateJavascripts () {
 }
 
 module.exports = {
-  /* exported for tests only */
   updateJavascripts
 }
-
-if (require.main === module) {
-  updateJavascripts()
-}

lib/_update/update-scss/index.js

@@ -8,7 +8,9 @@ const {
   removeLegacyIE8Sass
 } = require('./update_scss')
 
-removeKitSassFromApplicationSass()
-removeKitSassFromAppSassPath(appSassPatternsPath, libSassPatternsPath)
-removeKitSassFromAppSassPath(appSassPath, libSassPath)
-removeLegacyIE8Sass()
+module.exports.updateScss = function () {
+  removeKitSassFromApplicationSass()
+  removeKitSassFromAppSassPath(appSassPatternsPath, libSassPatternsPath)
+  removeKitSassFromAppSassPath(appSassPath, libSassPath)
+  removeLegacyIE8Sass()
+}

update.sh

@@ -170,6 +170,16 @@ copy () {
 
 	trap - ERR
 
+	update_gitignore
+}
+
+post () {
+	if [ -f 'update/lib/_update/post.js' ]; then
+		node 'update/lib/_update/post'
+	fi
+}
+
+finish () {
 	msg
 	msg "Your prototype kit files have now been updated, from version ${OLD_VERSION} to ${NEW_VERSION}."
 	msg 'If you need to make configuration changes, follow the steps at'
@@ -180,15 +190,6 @@ copy () {
 	update_gitignore
 }
 
-post () {
-	if [ -d "update/lib/_update/update-scss" ]; then
-		node "update/lib/_update/update-scss"
-	fi
-	if [ -f "update/lib/_update/update-javascripts.js" ]; then
-		node "update/lib/_update/update-javascripts"
-	fi
-}
-
 if [ "$0" == "${BASH_SOURCE:-$0}" ]
 then
 	check
@@ -197,4 +198,5 @@ then
 	extract
 	copy
 	post
+	finish
 fi