Allow multiple one-line imports

I usually import modules in a single import statement like so:

from __future__ import absolute_imports, unicode_literals

reorder-python-imports demands each import to be placed on seperate lines. Isort has this as a config option: force_single_line

[asottile]

I’m probably not going to implement this. The README has been updated with this rationale for the current style output.

That said, it’s now easier to use isort through pre-commit with correct import classification via seed-isort-config.

[Dinoshauer]

I’ll have a look at implementing it in #_get_steps when I get some time again