Vendor dependencies

Let's see how I like this workflow.

vendor/lock_api/Cargo.toml

@@ -0,0 +1,49 @@
+# 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 = "lock_api"
+version = "0.4.9"
+authors = ["Amanieu d'Antras <amanieu@gmail.com>"]
+description = "Wrappers to create fully-featured Mutex and RwLock types. Compatible with no_std."
+keywords = [
+    "mutex",
+    "rwlock",
+    "lock",
+    "no_std",
+]
+categories = [
+    "concurrency",
+    "no-std",
+]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/Amanieu/parking_lot"
+
+[dependencies.owning_ref]
+version = "0.4.1"
+optional = true
+
+[dependencies.scopeguard]
+version = "1.1.0"
+default-features = false
+
+[dependencies.serde]
+version = "1.0.126"
+optional = true
+default-features = false
+
+[build-dependencies.autocfg]
+version = "1.1.0"
+
+[features]
+arc_lock = []
+nightly = []