use openqa-python client instead of subprocess calling
    
    Summary:
    Since adamw created Python client for OpenQA, we
    can use it instead of calling Perl in subprocess. It simplyfies
    usage and special code for running in Docker is no longer needed.
    This version requires user to create configuration file either
    in `/etc/openqa/client.conf` or in `~/.config/openqa/client.conf`
    with the same KEY and SECRET as in host machine.
    
    To execute jobs in Docker, just specify correct server and
    port (probably `[localhost:8080]`) in configuration file.
    
    Only problem remains with self-signed certificate. It's
    necessary to either disable SSL cert verifying, import
    self-signed certificate or use HTTP instead of HTTPS in Docker,
    see https://github.com/os-autoinst/openQA-python-client/pull/1.
    
    Test Plan: Tested on running tests for compose F22 Final RC1.
    
    Reviewers: adamwill, jskladan
    
    Subscribers: tflink
    
    Differential Revision: https://phab.qadevel.cloud.fedoraproject.org/D425