Examples recommend using chaiAsPromised but it has problems with some promises.

chaiAsPromised doesn't properly handle rejections, and constantly reports true for some `spectron` methods when using some Promised methods. For example:

``` js
it("should be true", function() {
let val = this.app.electron.remote.getGlobal("appConfig").then(v => { return v.val })
assert.eventually.equal(
val, true
)
})
```

Always returns true for us, and never actually causes an assertion failure because there was a rejection with the object having an error. We could catch it, but then what is the point of chaiAsPromised at that point?

---

I propose the documentation also recommend a better way to deal with promises if they are using ES7.

``` js
it("should be true", async function() {
let config = await this.app.electron.remote.getGlobal("appConfig")
assert.equal(
config.val, true
)
})
```

If this is acceptable, I'm happy to send a pull request.

The issue names no documentation file or test. Start by locating the examples that recommend chaiAsPromised and reviewing how Spectron promise-based tests are documented. Done means the relevant guidance presents the proposed async/await approach, or clearly explains the supported alternative.

Written by the indexing model from the issue text.