Update requirements.txt

[FuhuXia]

Attempted to fix some errors on this outdated repo. Fixed some by updating the dependencies, but now it generates some other errors that need the repo maintainer to work it out. I can see there are two errors at this point.

Exception: Indicator 15.8.1 failed wide-to-tidy conversion - invalid source data.

and

Traceback (most recent call last):
  File "scripts/check_data.py", line 22, in <module>
    status = main()
  File "scripts/check_data.py", line 16, in main
    status = status & sdg.check_all_csv()
AttributeError: module 'sdg' has no attribute 'check_all_csv'