unable to install supervisor on python 3

[lastmeta]

readme says

Supervisor is intended to work on Python 3 version 3.4 or later and on Python 2 version 2.7.

I'm on 3.6.4.

I go to http://supervisord.org/ and use the pip install they suggest:

sudo python -m pip install --index-url https://pypi.org/simple/ --trusted-host pypi.org supervisor
Collecting supervisor==3.3.5
  Using cached https://files.pythonhosted.org/packages/ba/65/92575a8757ed576beaee59251f64a3287bde82bdc03964b89df9e1d29e1b/supervisor-3.3.5.tar.gz
    Complete output from command python setup.py egg_info:
    Supervisor requires Python 2.4 or later but does not work on any version of Python 3.  You are using version 3.6.4 (default, Dec 19 2017, 14:48:12)
    [GCC 4.8.5 20150623 (Red Hat 4.8.5-16)].  Please install using a supported version.

Supervisor requires Python 2.4 or later but does not work on any version of Python 3. You are using version 3.6.4

Am I installing it incorrectly?

[mnaberez]

Duplicate of #1060