Vendor dependencies

Let's see how I like this workflow.

vendor/users/Cargo.toml

@@ -0,0 +1,39 @@
+# 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 = "users"
+version = "0.11.0"
+authors = ["Benjamin Sago <ogham@bsago.me>"]
+exclude = ["/.rustfmt.toml", "/.travis.yml"]
+description = "Library for accessing Unix users and groups"
+documentation = "https://docs.rs/users/"
+readme = "README.md"
+license = "MIT"
+repository = "https://github.com/ogham/rust-users"
+[dependencies.libc]
+version = "0.2"
+
+[dependencies.log]
+version = "0.4"
+optional = true
+default_features = false
+[dev-dependencies.env_logger]
+version = "0.7"
+features = []
+default_features = false
+
+[features]
+cache = []
+default = ["cache", "mock", "logging"]
+logging = ["log"]
+mock = []