ait.hold context manager does not support mouse keys

[Dog]

The ait.hold context manager does not support mouse keys.

This means you can't hold right mouse button, while clicking left mouse button.

Example:

    import ait

    with ait.hold("RMB"):
        ait.click("LMB")

[Lonami]

Feel free to send a PR, as I won't have the time to do it myself in the near future.