slate beta regression

[est31]

slate version 1.3.0 test-regressed from stable to beta (full log):

Aug 16 21:51:06.438 INFO blam! ---- config::tests::it_uses_the_homedir_as_default_path stdout ----
Aug 16 21:51:06.439 INFO blam! 	thread 'config::tests::it_uses_the_homedir_as_default_path' panicked at 'assertion failed: `(left == right)`
Aug 16 21:51:06.439 INFO blam!   left: `"/home/cargobomb/.slate"`,
Aug 16 21:51:06.439 INFO blam!  right: `"/tmp/slate"`', src/config.rs:87:8
Aug 16 21:51:06.439 INFO blam! note: Run with `RUST_BACKTRACE=1` for a backtrace.

cc @jhbabon

[alexcrichton]

Racy test, global state with environment variables.

[jhbabon]

Yes, sorry about that. I'll try to fix the test so it doesn't happen again.