Vendor dependencies

Let's see how I like this workflow.

vendor/wasm-bindgen/tests/unwrap_throw.rs

@@ -0,0 +1,23 @@
+extern crate wasm_bindgen;
+use wasm_bindgen::prelude::*;
+
+#[test]
+fn unwrap_throw_ok() {
+    assert_eq!(Some(42).unwrap_throw(), 42);
+    let x: Result<i32, ()> = Ok(42);
+    assert_eq!(x.unwrap_throw(), 42);
+}
+
+#[test]
+#[should_panic]
+fn unwrap_throw_none() {
+    let x: Option<i32> = None;
+    x.unwrap_throw();
+}
+
+#[test]
+#[should_panic]
+fn unwrap_throw_err() {
+    let x: Result<i32, ()> = Err(());
+    x.unwrap_throw();
+}