GetOrganelle v1.7.2

1. slim_graph.py: fix a bug in parsing options
2. automatically adding --phred-offset to avoid hammer failures
3. MergingHistory and ConsensusHistory added, in replace of using the names to detect merging history
4. Compatible with flye gfa format
5. Scaffolding function bug fixed & improved
6. get_organelle_config.py: example typo fixed