Mismatched Syntax

It seems that some of the examples in the readme don't use the same syntax that's specified in the [antonmi/espec](https://github.com/antonmi/espec) repo. For example:

```
expect(new_changeset.errors).to have(error)
```

Should be:

```
expect(new_changeset.errors) |> to(have error)
```

Correct?

Thanks for creating such a great library! I'm really enjoying using it. 🙂