Return what I really expect __iter__ to do
Return what I really expect __iter__ to do

What convinces me of this is what happens if you do `list(NullObject())`. The
list should be empty but instead you received a single-element list with the
NullObject instance in it. That's just wrong.

jim-minter/github3.py,agamdua/github3.py,degustaf/github3.py,balloob/github3.py,itsmemattchung/github3.py,sigmavirus24/github3.py,christophelec/github3.py,ueg1990/github3.py,krxsky/github3.py,h4ck3rm1k3/github3.py,icio/github3.py,wbrefvem/github3.py