Created by: DanProudfoot
Hi there
This is my first pull request for anything, I think, so let me know if I'm breaking protocol.
I'm not exactly hot on Node backend stuff really, but the intention here was to allow the build directory to be set to anything (excluding a few reserved names like public, src, .git and node_modules).
My rationale came from doing a bit of Cordova development, where the web files are expected to be in a 'www' folder instead of 'build'
I have tested this myself that it outputs files into the specified folder, and it will throw an error if the path is forbidden.
I don't know what to do re: adding real tests, but I'm willing to take pointers