WIP: Add grobal alignment test case.
Add test case.
Add calcurate cell score function.
WIP: add function of filling in cell.
WIP: Add arguments of neighbor cells.
WIP: setting previous cell.
Unified variable names.
Fix function of fill in cell.
Fix function of print score table.
Add base of trace back.
WIP: Add alignment.
Add fucntion of traceback.
Add test cases.
Remove printing debug code.