py3: pass the path in hg.repository() as bytes

This make test-ancestor.py pass on Python 3.

contrib/python3-whitelist

@@ -1,3 +1,4 b''
+test-ancestor.py
 test-check-execute.t
 test-check-shbang.t
 test-contrib-check-code.t

tests/test-ancestor.py

@@ -225,7 +225,7 b' dagtests = ['
 def test_gca():
     u = uimod.ui.load()
     for i, dag in enumerate(dagtests):
-        repo = hg.repository(u, 'gca%d' % i, create=1)
+        repo = hg.repository(u, b'gca%d' % i, create=1)
         cl = repo.changelog
         if not util.safehasattr(cl.index, 'ancestors'):
             # C version not available