fix flake8 found problems

Author: barry-scott

Diff for: git/cmd.py

@@ -614,7 +614,7 @@ def execute(self, command,
                          cwd=cwd,
                          bufsize=-1,
                          stdin=istream,
-                         stderr=PIPE, 
+                         stderr=PIPE,
                          stdout=PIPE if with_stdout else open(os.devnull, 'wb'),
                          shell=self.USE_SHELL,
                          close_fds=(os.name == 'posix'),  # unsupported on windows

Diff for: git/remote.py

@@ -8,7 +8,6 @@
 import re
 import os
 
-from .exc import GitCommandError
 from .config import (
     SectionConstraint,
     cp,