A long time coming this commit removes the `flate` crate in favor of the
`flate2` crate on crates.io. The functionality in `flate2` originally flowered
out of `flate` itself and is additionally the namesake for the crate. This will
leave a gap in the naming (there's not `flate` crate), which will likely cause a
particle collapse of some form somewhere.
This commit removes the libuv and gyp submodules, as well as all build
infrastructure related to them.
For more context, see the [runtime removal
RFC](https://github.com/rust-lang/rfcs/pull/230)
[breaking-change]
