Fix stray bad isort.
I'm not sure how this snuck in master, but cleans it up.
import sys
-from pex.pep425tags import get_abi_tag, get_abbr_impl, get_impl_ver
+from pex.pep425tags import get_abbr_impl, get_abi_tag, get_impl_ver
from pex.platforms import Platform
EXPECTED_BASE = [('py27', 'none', 'any'), ('py2', 'none', 'any')]
