fix hang build

tox.ini

@@ -12,13 +12,12 @@ deps =
     pytest-cov
     pytest-sanic
     pytest-sugar
-    pytest-xdist
     aiohttp>=2.3
     chardet<=2.3.0
     beautifulsoup4
     gunicorn
 commands =
-    pytest tests -n 4 --cov sanic --cov-report= {posargs}
+    pytest tests --cov sanic --cov-report= {posargs}
     - coverage combine --append
     coverage report -m