fixed bug in merge_stat for hg19

fixed bug in merge_stat for hg19

added option regions_from_tag to umi_error_correct.py

added missing line of code in umi_error_correct.py

fixed bug when index i-1 not exist

removed N in consensus reads from cons file

fixed bug in get_position_coverage causing deletions to disappear

uncommented merge duplicate positions

updated Dockerfile

Update README.md