Set jupyter_server floor, take 2

Author: kevin-bates

setup.py

@@ -55,7 +55,7 @@
     install_requires=[
         'jupyter_client>=7.4.4',
         'jupyter_core>=4.12,!=5.0.*',
-        'jupyter_server<=2.0',  # Cap jupyter_server until identity_provider attribute can be worked out
+        'jupyter_server>=2.0',
         'traitlets>=5.6.0',
         'tornado>=6.2.0',
         'requests>=2.7,<3.0'