Changeseq

refseq ID is replaced by gene name

- update visualization, off-targets will be annotated when homer is installed

- removed dependencies on ECDF from statmodel

- fixed a read count output error

- Add YAML parameter to specify fixed threshold for detection
- Add YAML parameter to specify read length for analysis
- Add YAML parameter to specify PAM sequence
- Fix the code to get the ‘realigned target sequence’ to use the new feature in regex library that provides fuzzy_changes
- Fix bug in visualization.py where it stops when no off-targets are found
- Add control read counts to output
- reformat "identified matches txt"
- updated revcomp function to address SNPs