hg: support Mercurial 5.8

Some 'remote:' messages changed to appear on stderr.

kallithea/tests/other/test_vcs_operations.py

@@ -558,7 +558,7 b' class TestVCSOperations(base.TestControl'
         stdout, stderr = Command(base.TESTS_TMP_PATH) \
             .execute(vt.repo_type, 'clone', clone_url, dest_dir, ignoreReturnCode=True)
         if vt.repo_type == 'hg':
-            assert 'preoutgoing.testhook hook failed' in stdout
+            assert 'preoutgoing.testhook hook failed' in stdout + stderr
         elif vt.repo_type == 'git':
             assert 'error: 406' in stderr
 

setup.py

@@ -63,7 +63,7 b' requirements = ['
     "URLObject >= 2.3.4, < 2.5",
     "Routes >= 2.0, < 2.5",
     "dulwich >= 0.19.0, < 0.20",
-    "mercurial >= 5.2, < 5.8",
+    "mercurial >= 5.2, < 5.9",
     "decorator >= 4.2.1, < 4.5",
     "Paste >= 2.0.3, < 3.5",
     "bleach >= 3.0, < 3.1.4",