Revert "Fix PEP8 issues."

This reverts commit b4348ff7a71b51470a52a47f914bf09c63a87fce.

Required as 464889896121c3045c2b2b3098c88eeb6b8457bd broken.
Revert "Remove user='root' parameter."

This reverts commit 464889896121c3045c2b2b3098c88eeb6b8457bd.

This change was broken, user='root' is not the default, and we break
stuff (e.g. copying files to schroot) by making user='root' the default.
Don't use sudo unless we have to.