Vendor dependencies

Let's see how I like this workflow.

vendor/pin-project-lite/tests/expandtest.rs

@@ -0,0 +1,43 @@
+#![cfg(not(miri))]
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+use std::{
+    env,
+    process::{Command, ExitStatus, Stdio},
+};
+
+const PATH: &str = "tests/expand/**/*.rs";
+
+#[rustversion::attr(not(nightly), ignore)]
+#[test]
+fn expandtest() {
+    let is_ci = env::var_os("CI").is_some();
+    let cargo = &*env::var("CARGO").unwrap_or_else(|_| "cargo".into());
+    if !has_command(&[cargo, "expand"]) || !has_command(&[cargo, "fmt"]) {
+        if is_ci {
+            panic!("expandtest requires rustfmt and cargo-expand");
+        }
+        return;
+    }
+
+    let args = &["--all-features"];
+    if is_ci {
+        macrotest::expand_without_refresh_args(PATH, args);
+    } else {
+        env::set_var("MACROTEST", "overwrite");
+        macrotest::expand_args(PATH, args);
+    }
+}
+
+fn has_command(command: &[&str]) -> bool {
+    Command::new(command[0])
+        .args(&command[1..])
+        .arg("--version")
+        .stdin(Stdio::null())
+        .stdout(Stdio::null())
+        .stderr(Stdio::null())
+        .status()
+        .as_ref()
+        .map(ExitStatus::success)
+        .unwrap_or(false)
+}