salt: salt-ssh doesn't support python-tornado 5.0.2

Description of Issue/Question

I am seeing this problem with Fedora 28 and python 2.7.15 locally, and Ubuntu 14.04 remotely with python 2.7.6. Both have python-certifi installed. I just started seeing this have upgrading to 2018.3.1 from 2018.3.0.

    ----------
    _error:
        Failed to return clean data
    retcode:
        0
    stderr:
        Traceback (most recent call last):
          File "/var/tmp/.ngrennan_e1f3ee_salt/salt-call", line 15, in <module>
            salt_call()
          File "/var/tmp/.ngrennan_e1f3ee_salt/py2/salt/scripts.py", line 395, in salt_call
            import salt.cli.call
          File "/var/tmp/.ngrennan_e1f3ee_salt/py2/salt/cli/call.py", line 8, in <module>
            import salt.cli.caller
          File "/var/tmp/.ngrennan_e1f3ee_salt/py2/salt/cli/caller.py", line 18, in <module>
            import salt.loader
          File "/var/tmp/.ngrennan_e1f3ee_salt/py2/salt/loader.py", line 28, in <module>
            import salt.utils.event
          File "/var/tmp/.ngrennan_e1f3ee_salt/py2/salt/utils/event.py", line 70, in <module>
            import tornado.iostream
          File "/var/tmp/.ngrennan_e1f3ee_salt/py2/tornado/iostream.py", line 40, in <module>
            from tornado.netutil import ssl_wrap_socket, _client_ssl_defaults, _server_ssl_defaults
          File "/var/tmp/.ngrennan_e1f3ee_salt/py2/tornado/netutil.py", line 44, in <module>
            _client_ssl_defaults = ssl.create_default_context(
        AttributeError: 'module' object has no attribute 'create_default_context'

Downgrading from python2-tornado-5.0.2-2.fc28.x86_64 to python-tornado-4.2.1-4.fc28.x86_64(built from the fc24 src.rpm) fixes it.

Setup

Steps to Reproduce Issue

salt-ssh -i hostname

Versions Report

Salt Version:
           Salt: 2018.3.1
 
Dependency Versions:
           cffi: 1.11.5
       cherrypy: Not Installed
       dateutil: 2.6.1
      docker-py: Not Installed
          gitdb: Not Installed
      gitpython: Not Installed
          ioflo: Not Installed
         Jinja2: 2.10
        libgit2: Not Installed
        libnacl: Not Installed
       M2Crypto: Not Installed
           Mako: 1.0.6
   msgpack-pure: Not Installed
 msgpack-python: 0.5.6
   mysql-python: Not Installed
      pycparser: 2.14
       pycrypto: 2.6.1
   pycryptodome: Not Installed
         pygit2: Not Installed
         Python: 2.7.15 (default, May 16 2018, 17:50:09)
   python-gnupg: Not Installed
         PyYAML: 3.12
          PyZMQ: 17.0.0
           RAET: Not Installed
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 5.0.2
            ZMQ: 4.1.6
 
System Versions:
           dist: fedora 28 Twenty Eight
         locale: UTF-8
        machine: x86_64
        release: 4.17.3-200.fc28.x86_64
         system: Linux
        version: Fedora 28 Twenty Eight