BUG: fix Pymc sampler import
My previous attempt to fix this (!1348 (merged)) was incomplete. I've actually tested that the example runs this time...
I also noticed a few outdated references to pymc3 rather than pymc in comments that I fixed.
My previous attempt to fix this (!1348 (merged)) was incomplete. I've actually tested that the example runs this time...
I also noticed a few outdated references to pymc3 rather than pymc in comments that I fixed.