Vendor dependencies

Let's see how I like this workflow.

vendor/pin-project-lite/Cargo.toml

@@ -0,0 +1,45 @@
+# 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"
+rust-version = "1.37"
+name = "pin-project-lite"
+version = "0.2.9"
+exclude = [
+    "/.*",
+    "/tools",
+]
+description = """
+A lightweight version of pin-project written with declarative macros.
+"""
+keywords = [
+    "pin",
+    "macros",
+]
+categories = [
+    "no-std",
+    "rust-patterns",
+]
+license = "Apache-2.0 OR MIT"
+repository = "https://github.com/taiki-e/pin-project-lite"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dev-dependencies.rustversion]
+version = "1"
+
+[dev-dependencies.static_assertions]
+version = "1"
+
+[dev-dependencies.trybuild]
+version = "1.0.49"