Yatta

- Update edit records command to accept "0" for record_id to edit the last record

Fixed issue with weekly timesheets and plots adding durations over multiple days.

Remove unused dependencies.

Support python v3.6 (^3.6.1)

- Timesheets w/ per-task summary
- Daily, Weekly
- In-terminal visualization of summary statistics
- Daily, Weekly, Monthly
- Tab completion
- Config management
- Various bug fixes

Minor dep fixes, linting