Merge remote-tracking branch 'origin/master' into test_refactor_dqc_wrapper

# Conflicts:
#	dqc_wrapper/checker.py
#	dqc_wrapper/test00_file_format.py
#	dqc_wrapper/test01_standard_compliance.py
#	dqc_wrapper/test02_spatial_completeness.py
#	dqc_wrapper/test05_temporal_consistency.py
#	dqc_wrapper/test06_valid_ranges.py