Do not let coveralls fail the build

Signed-off-by: Michal Čihař <michal@cihar.com>
Merge branch 'MAINT_4_2_13' into QA_4_2
Merge branch 'QA_4_2' into MAINT_4_3_0

Conflicts:
	.travis.yml
Merge branch 'MAINT_4_3_0' into QA_4_3