A little suggest about supporting Windows system commands

[zhaoxiujie]

My OS is Windows. I need to debug my program locally. But this tool doesn't seem to support executing Windows system commands such as 'dir' ,'chdir' ,etc. So I have to manually modify the following code:
diff_cover/command_runner.py # execute() line:27
process = subprocess.Popen(command, stdout=stdout_pipe, stderr=stdout_pipe)
to
process = subprocess.Popen(command, stdout=stdout_pipe, stderr=stdout_pipe,shell=True,cwd=None)

So I suggest to add the 'shell' and 'cwd' parameters when using the class Popen.