Sort imports in requirements.txt
-# When you change this file please also update `doc/doc-requirements.txt`
-# which needs to be kept in sync manually.
-kubernetes
-escapism
-traitlets
+# Keep this file in sync with `doc/doc-requirements.txt`!
docker
+escapism
jinja2
-prometheus_client
-python-json-logger
-jupyterhub
jsonschema
+jupyterhub
+kubernetes
+prometheus_client
pycurl
+python-json-logger
tornado>=5.1
-
+traitlets
