CLN: change print to print() in docs

[alefnula]

closes #4967

print statements refactoring

[jreback]

@cpcloud can you build these docs just to check?

[jreback]

@alefnula fyi....in fut make the top of the PR like I did here; then when merged willl auto close the issue
and make the title reflect the issue for easy viewing

thanks! these r gr8

[cpcloud]

@jreback sure thing

[cpcloud]

hm numpydoc not compatible with py3 :(

[cpcloud]

at least the version we're using isn't

[alefnula]

@cpcloud But this is also valid py2 code :-/

[cpcloud]

yep those are building

[cpcloud]

@jreback there's that to_datetime failure (@alefnula, unrelated to ur changes) but otherwise things are 👌 in py2 land

[jreback]

right, I think dan birken still fixing that up