fix import moved above a future import

[Hanaasagi]

As you can see in issue #459, autopep8 will move import aboved a from __future__ import xxx, leading a syntax error.

Following code

from __future__ import print_function
a = 1
import os

will be converted to

import os
from __future__ import print_function
a = 1

So, I wanna to pull request to solve it : )

[coveralls]

Coverage increased (+0.02%) to 98.617% when pulling 9cd6ad5 on Hanaasagi:fix-import-moved-above-future-import into 40bcf6f on hhatto:master.

[coveralls]

Coverage increased (+0.02%) to 98.617% when pulling 9cd6ad5 on Hanaasagi:fix-import-moved-above-future-import into 40bcf6f on hhatto:master.

[hhatto]

@Hanaasagi

Thanks for your contribution!!
LGTM 👍