Windows installer's conda step fails if it's run with a directory with a space in the path

[vlofgren]

Windows installer's conda step fails if it's run with a directory with a space in the path.

It seems this is due to miniconda not dealing with with paths that contain spaces. Perhaps it would be a good idea to warn about this from the installer, as it takes a fair bit of detective work to identify the issue from the symptoms.

Steps to reproduce: Run the installer from a directory like "C:\I Have Spaces"

[lukaszliniewicz]

Yes, I will add a check. Thanks!