.gitlab-ci.yml: Make lcov_artifact and junit artifacts cohabitate

See !289
9 jobs for feature-a/3444-artificats-junit in 41 minutes and 25 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Test Tools
passed test_tools #171127

00:00:05

 
  Test Unit
passed test_algo_unit #171128

00:02:25

 
  Test Shouldvdj
passed test_algo_shouldvdj #171129

00:17:42

 
  Test Functional
passed test_algo_should #171130

00:13:01

 
  Coverage
passed algo_coverage #171131

00:00:06

88.5%
 
  Prepare Release
manual prepare_release #171132
allowed to fail manual
 
  Valgrind Unit
passed algo_valgrind_unit #171133
valgrind

00:08:03

 
  Valgrind Functional
manual algo_valgrind_functional #171134
valgrind allowed to fail manual
 
  Multiple Tests
manual test_various_compilers_manual #171135
several-compilers allowed to fail manual