Use gettempdir() for sockets

[eas604]

Change uses tempfile.gettempdir() for working with sockets, rather than hard-coding /tmp. This addresses #12 .

[jonathanslenders]

Thanks a lot @eas604!
Merged in: 70d9901

(I also wonder whether we can get rid of the bit of code duplication that we have here. That would be a different commit.)

[eas604]

Which code duplication do you mean? The multiple locations where the socket file is defined?

[jonathanslenders]

Yes, that is a small bit of duplication that I introduced in the beginning. Maybe nothing to worry about.