BUG #15739: PgAdmin4 4.4 does not work with latest psycopg2 (2.8.1)

The following bug has been logged on the website:

Bug reference:      15739
Logged by:          Jamie Carl
Email address:      jamie@hazaarlabs.com
PostgreSQL version: 11.2
Operating system:   Ubuntu 18.10
Description:

Installed in server mode using the python wheel package, my current version
of psycopg2 was 2.8.1.  Installing pgAdmin4 succeeded with no errors, but
when expanding servers in the browser tree, I would get the error
"'psycopg2.extensions.Column' object has no attribute '_asdict'".
Downgrading to psycopg2 library version 2.7.7 and everything starts working.
 

When installing the python wheel package, the requirement appears to be for
psycopg2>=2.7.7 but I think this should also include <= 2.8.0 or something
(not sure how, I'm a PHP guy).