Post-hoc testing support for LM's

[Meganton]

Hey, it would be great if the Linear Models had the same post-hoc-testing capabilities as the LMEM's. So to add a function linear_model.post_hoc(), with equal functionality as the LMEM's have.

[ejolly]

Yea that would be great, but just haven't had the time to implement something like that because I'm borrowing the post hoc functionality in LMMs from the underlying R packages.

I'd have to write something custom to do the equivalent for linear models. Going to leave this open in case anyone has time to contribute!