Merge pull request #43 from blink1073/tornado-5-compat

Update test for tornado 5

jupyterlab_launcher/tests/utils.py

@@ -73,6 +73,9 @@ def tmp(*parts):
                                workspaces_dir=pjoin(here, 'workspaces'))
 
         def start_thread():
+            if 'asyncio' in sys.modules:
+                import asyncio
+                asyncio.set_event_loop(asyncio.new_event_loop())
             app = cls.notebook = LabLauncherApp(
                 port=cls.port,
                 port_retries=0,