Vendor dependencies

Let's see how I like this workflow.

vendor/parking_lot_core/Cargo.toml

@@ -0,0 +1,68 @@
+# 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 = "parking_lot_core"
+version = "0.9.5"
+authors = ["Amanieu d'Antras <amanieu@gmail.com>"]
+description = "An advanced API for creating custom synchronization primitives."
+keywords = [
+    "mutex",
+    "condvar",
+    "rwlock",
+    "once",
+    "thread",
+]
+categories = ["concurrency"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/Amanieu/parking_lot"
+
+[dependencies.backtrace]
+version = "0.3.60"
+optional = true
+
+[dependencies.cfg-if]
+version = "1.0.0"
+
+[dependencies.petgraph]
+version = "0.6.0"
+optional = true
+
+[dependencies.smallvec]
+version = "1.6.1"
+
+[dependencies.thread-id]
+version = "4.0.0"
+optional = true
+
+[features]
+deadlock_detection = [
+    "petgraph",
+    "thread-id",
+    "backtrace",
+]
+nightly = []
+
+[target."cfg(target_os = \"redox\")".dependencies.redox_syscall]
+version = "0.2.8"
+
+[target."cfg(unix)".dependencies.libc]
+version = "0.2.95"
+
+[target."cfg(windows)".dependencies.windows-sys]
+version = "0.42.0"
+features = [
+    "Win32_Foundation",
+    "Win32_System_LibraryLoader",
+    "Win32_System_SystemServices",
+    "Win32_System_WindowsProgramming",
+]