fix(webpack): fix issue where bundles output to build dir sub directo…

[michaelgeorgeattard]

…ry are not emitted

Short description of what this resolves:

Webpack not emitting bundles in build directory's subdirs.

Fixes: #932

[alan-agius4]

This is also needed if you want to have different build directories 👍

[WhatsThatItsPat]

@alan-agius4 Please don't spam the watchers of this repo (along with the Ionic team) with comments like this. A thumbs up emoji does absolutely nothing to further the conversation.

GitHub introduced reactions for this express purpose. When you feel the need to voice your approval, please use reactions instead of filling everyone's inboxes.