AlignmentDBVisualisationTool.importmatplotlib test fails intermittently

AlignmentDBVisualisationTool.importmatplotlib fails because of the following unexpected content in stderr:

Fontconfig error: Cannot load default config file

thanks to @cgobelbu and @chasse for reporting

The underlying reason for that message is described in https://its.cern.ch/jira/browse/LBCORE-2000

There are two things we should do

1. Make sure the matplotlib font cache is in a new (temp) directory every time the test runs
2. Temporarily set FONTCONFIG_PATH

added failing build label

changed the description

changed the description

mentioned in merge request !167 (merged)

@rmatev is this issue still relevant?

gentle ping @rmatev

this was fixed, see JIRA issue for details

closed