Make BeakerLib logging less verbose
    
    Logs from Beaker jobs are normally very brief, with the standard
    output/error containing detailed information. Make ipa-run-tests
    with BeakerLib plugin follow this convention.
    
    Only include INFO and higher level messages in the Beaker logs.
    Downgrade several message levels to DEBUG.
    Log to console using Python logging instead of showing the Beaker logs.
    
    Since ipa-run-tests sets up its own logging, Nose's own log
    handling just causes duplicate messages. Disable it with --nologcapture.