mock-fs-require-fix was always kind of a huge hack. It's no longer
necessary, with an FS API that does everything it used to.
This removes a lot of other hacks from test/main.js, which is nice.
The new FS module is an abstraction layer over the built-in fs module.
The main reason it exists is because I need an abstraction layer I can
disable writing from. But that'll be in another commit.
Currently, mine is better because:
- paths are always relative to PS's base directory
- Promises (seriously wtf Node Core what are you thinking)
- PS-style API: FS("foo.txt").write("bar") for easier argument order
- mkdirp
This also increases the minimum supported Node version from v6.0 to
v7.7, because we now use async/await. Sorry for the inconvenience!
