Added heel sequence parameters and updated CSV/print outputs to display heel sequences if given. Removed a debug file.
edited position of heel sequence output from end of sequence string to beginning.
Fixed case-sensitivity issue.

Heel sequences now case insensitive at input; will output whatever case
was input.

Added .gitignore file to ensure debug and log files are not committed.
Merge branch 'heelseqdev'

Conflicts:
	Primer_design.py <— merge issue fixed