Vendor dependencies

Let's see how I like this workflow.

vendor/js-sys/CHANGELOG.md

@@ -0,0 +1,72 @@
+# `js-sys` Change Log
+
+--------------------------------------------------------------------------------
+
+## Unreleased
+
+Released YYYY-MM-DD.
+
+### Added
+
+* TODO (or remove section if none)
+
+### Changed
+
+* TODO (or remove section if none)
+
+### Deprecated
+
+* TODO (or remove section if none)
+
+### Removed
+
+* TODO (or remove section if none)
+
+### Fixed
+
+* TODO (or remove section if none)
+
+### Security
+
+* TODO (or remove section if none)
+
+--------------------------------------------------------------------------------
+
+## 0.2.1
+
+Released 2018-08-13.
+
+### Added
+
+* Added bindings to `Array.prototype.splice`.
+* Added bindings to `RegExp`.
+* Added bindings to `ArrayBuffer.prototype.byteLength`.
+* Started adding the `#[wasm_bindgen(extends = ...)]` attribute to various JS
+  types.
+* Added bindings to `EvalError`.
+* Added bindings to `Promise`. See the new `wasm-bindgen-futures` crate for
+  integrating JS `Promise`s into Rust `Future`s.
+* Added bindings to `JSON.{parse,stringify}`.
+* Added bindings to `Array.of`.
+* Added bindings to `Intl.Collator`.
+* Added bindings to `Object.assign`.
+* Added bindings to `Object.create`.
+* Added bindings to `RangeError`.
+* Added bindings to `ReferenceError`.
+* Added bindings to `Symbol.unscopables`.
+* Added bindings to `URIError`.
+* Added bindings to `SyntaxError`.
+* Added bindings to `TypeError`.
+
+### Changed
+
+* The `Intl` namespace was previously a bound object with static methods hanging
+  off of it. It is now a module with free functions, and nested types.
+
+--------------------------------------------------------------------------------
+
+## 0.2.0
+
+Released 2018-07-26.
+
+Initial release!