v1.0.0.alpha1

• Drop support for anything below Opal v1.6.0.alpha1

• Update to the latest RSpec versions

• Vendor-in diff-lcs

• Rework the async logic to use the await feature of Opal

  • If you use async features, it's crucial to use a # await: *await* magic comment (this will cause any call to a method containing an await word to be compiled with an await ES8 keyword)
  • Both let and subject that return a promise (ie. are async) must be referenced with an .await method
  • In around blocks, you must call example.run_await instead of just example.run
  • Only PromiseV2 is supported (PromiseV1 may work, but you should migrate your application to use PromiseV2 nevertheless, in Opal 2.0 it will become the default)