[2.7] bpo-30108: Restore sys.path in test_site by vstinner · Pull Request #1459 · python/cpython

Add setUpModule() and tearDownModule() functions to test_site to
save/restore sys.path at the module level to prevent warning if the
user site directory is created, since site.addsitedir() modifies
sys.path.
(cherry picked from commit b85c136)