Vendor dependencies

Let's see how I like this workflow.

vendor/windows_x86_64_gnu/Cargo.toml

@@ -0,0 +1,23 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
+name = "windows_x86_64_gnu"
+version = "0.42.0"
+authors = ["Microsoft"]
+description = "Code gen support for the windows crate"
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/microsoft/windows-rs"
+
+[package.metadata.docs.rs]
+default-target = "x86_64-pc-windows-msvc"
+targets = []