Vendor dependencies

Let's see how I like this workflow.

vendor/bytes/Cargo.toml

@@ -0,0 +1,54 @@
+# 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 = "bytes"
+version = "1.3.0"
+authors = [
+    "Carl Lerche <me@carllerche.com>",
+    "Sean McArthur <sean@seanmonstar.com>",
+]
+description = "Types and traits for working with bytes"
+readme = "README.md"
+keywords = [
+    "buffers",
+    "zero-copy",
+    "io",
+]
+categories = [
+    "network-programming",
+    "data-structures",
+]
+license = "MIT"
+repository = "https://github.com/tokio-rs/bytes"
+
+[package.metadata.docs.rs]
+rustdoc-args = [
+    "--cfg",
+    "docsrs",
+]
+
+[dependencies.serde]
+version = "1.0.60"
+features = ["alloc"]
+optional = true
+default-features = false
+
+[dev-dependencies.serde_test]
+version = "1.0"
+
+[features]
+default = ["std"]
+std = []
+
+[target."cfg(loom)".dev-dependencies.loom]
+version = "0.5"