Autokattis

Some considerable changes in the UI/UX that made this update to be:
- `NUSKattis` now returns 403 upon access to problem statistics, which encourages the use of `problems_v2` for `NUSKattis`
- `NUSKattis` doesn't "give" you the problem statement right away when searching for one, so technically it is now inaccessible. This should only affect the tests removal
- Group/team name is officially a new column in the self-statistics page (both open and NUS Kattis), this affects `problems_v2` and `stats` methods
- Searching beyond the last page on the `problems` table will give you an empty table instead of wrapping around the last page

**Full Changelog**: https://github.com/RussellDash332/autokattis/compare/v1.6.4...v1.6.5

What's new:
- `problems_v2` method that runs faster due to possible gateway (error code 502 and 504) issues from `problems` especially for `NUSKattis`
- This only lists down the problem (ID)s and not the statistics such as the shortest/fastest solution

**Full Changelog**: https://github.com/RussellDash332/autokattis/compare/v1.6.3...v1.6.4

What's new:
- NUS course assignments are now displaying the problem name instead of the problem ID, so the ID has to be obtained from the hyperlink

**Full Changelog**: https://github.com/RussellDash332/autokattis/compare/v1.6.2...v1.6.3

What's new:
- Due to precision issues, the seaborn plot generated seems to combine multiple bins in one and let the neighboring bins empty, which is not an intended behavior

**Full Changelog**: https://github.com/RussellDash332/autokattis/compare/v1.6.1...v1.6.2

What's new:
- The `ranklist` method now supports query for top 100 users

**Full Changelog**: https://github.com/RussellDash332/autokattis/compare/v1.6...v1.6.1

What's new:
- `NUSKattis`-specific methods!
- `courses`: lists down all NUS courses that are currently ongoing and recently ended
- `offerings`: lists down all offerings from a particular NUS course
- `assignments`: lists down all assignments from a particular NUS course offering
- `new_get` and `new_post` methods to essentially increase the number of retries
- `<get/set>_<base_url/homepage>` methods for the sake of OOP
- Changes to login print message - it should be at the very end of the `__init__` method
- Minor bugfixes, e.g. the `1E+30` issue when there is no data to show on `problems`
- Remove strict versioning for `pandas` and `seaborn` requirement. There seems to be no apparent issue so far

**Full Changelog**: https://github.com/RussellDash332/autokattis/compare/v1.5...v1.6