manually create db-connection on test:purge.
Merge pull request #1101 from ontohub/fix_test_db_building

manually create db-connection on test:purge.
enforce hierarchy-sentences to end appropriately.
Merge pull request #1102 from ontohub/1100-fix_tree_generation

enforce hierarchy-sentences to end appropriately.
Merge branch 'staging' into 446-new_ontohub_oms_generalization