SCRUM#511: added linter to ci + solve linter problems

Signed-off-by: Rafael S Castilho <rsc15@inf.ufpr.br>
4 jobs for issue/511 in 8 minutes and 8 seconds (queued for 5 seconds)
Status Name Job ID Coverage
  Lint
passed lint_python #26951
debian-packaging

00:00:27

passed lint_shell #26950
debian-packaging

00:00:19

 
  Build
passed build #26952
debian-packaging

00:00:26

 
  Test
passed test #26953
ubuntu regular

00:07:15