Vendor dependencies

Let's see how I like this workflow.

vendor/pin-project-lite/tests/expand/pub/struct.rs

@@ -0,0 +1,11 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    pub struct Struct<T, U> {
+        #[pin]
+        pub pinned: T,
+        pub unpinned: U,
+    }
+}
+
+fn main() {}