easy rotate y-axis labels

[softloud]

I noticed the x labels were in your commits. As far as I know there isn't a helper function for the $y$-axis labels? This came up for me recently when I was doing a coord flip.

[jonocarroll]

I've only added the one helper so far, by all means rotating y should also have a helper. If you're keen you can add it yourself, otherwise consider it on the list.

[softloud]

Excellent idea, I should have a crack at this! Should be a straightforward adaptation of your other function.

[jonocarroll]

[jonocarroll]

If you're copying easy_rotate_x_labels() then don't forget to make note of #18 (or fix it in both 😜).