Remove home argument from get_timeline

[hadley]

Since according to https://developer.twitter.com/en/docs/twitter-api/v1/tweets/timelines/api-reference/get-statuses-home_timeline, you can only get the home timeline for the authenticated user (i.e. get_my_timeline())

[llrs]

The home argument changes the endpoint it is called:
api <- if (home) "/1.1/statuses/home_timeline" else "/1.1/statuses/user_timeline"
Perhaps it signals that it should be organized differently to better mimic Twitter API?

[hadley]

I think home makes sense in get_timeline_user() since get_timeline() and get_my_timeline() share a lot of code, so I'll deprecate it get_timeline() but otherwise leave it alone.