monotone: renamed subdirs to singular
monotone: renamed subdirs to singular

Former-commit-id: 92b8245d1deea710ccb65ee74e55e262e451191a [formerly 70ca9d02582b982574ed33cd2b597cb00174ffc0]
Former-commit-id: f4f12b689208316371e7d7c0803fa50b8216346a
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine