Vendor dependencies

Let's see how I like this workflow.

vendor/signal-hook-registry/Cargo.toml

@@ -0,0 +1,31 @@
+# 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 believe there's an error in this file please file an
+# issue against the rust-lang/cargo repository. If you're
+# editing this file be aware that the upstream Cargo.toml
+# will likely look very different (and much more reasonable)
+
+[package]
+name = "signal-hook-registry"
+version = "1.4.0"
+authors = ["Michal 'vorner' Vaner <vorner@vorner.cz>", "Masaki Hara <ackie.h.gmai@gmail.com>"]
+description = "Backend crate for signal-hook"
+documentation = "https://docs.rs/signal-hook-registry"
+readme = "README.md"
+keywords = ["signal", "unix", "daemon"]
+license = "Apache-2.0/MIT"
+repository = "https://github.com/vorner/signal-hook"
+[dependencies.libc]
+version = "~0.2"
+[dev-dependencies.signal-hook]
+version = "~0.3"
+[badges.maintenance]
+status = "actively-developed"
+
+[badges.travis-ci]
+repository = "vorner/signal-hook"