Alternate method of making temp data folder to account for domain-joined windows accounts #193

[kieranjol]

This is a fix for #193 and uses an alternative method (os.mkdir) instead of tempfile.mkdtemp to work correctly with domain-joined windows accounts with regards to permissions. I'm very open to any other methods of working around this issue!

[kieranjol]

It could be good to hear from @edsu as some tempfile issues arose before regarding permissions: #22 and this was the commit that introduced tempfile a7c44b5 in order to fix this issue around bag.save() #29

[edsu]

I left a note over on #193 to see if a small adjustment to how permissions from the directory to be bagged are being preserved on the payload directory. I think it's a bad smell that we are relying on a function designated as private. I am less concerned about the security implications since we are eventually setting them to match those of the original directory, and mkdtemp() was really only introduced in order to help in situations where there is already a file or directory named data.