4 Updates to main.py

[jharemza]

changes are as follows and listed in line sequence:

1. updated scrape_years function (line 155)
   • updated class name to match current class name.
2. updated scrape_helpful function (line 160)
   • added text.replace to return string; facilitates return of numerical value.
3. updated scrap_pros, scrape_cons, and scrape_advice (lines 176, 186, 196)
   • updated class name to match current class name.
4. fixed offset of "len(res) < args.limit" clause in while statement of main() (line 486)
   • changed "len(res)" to "len(res) + 1" b/c res is 0 indexed and args.limit is 1 indexed
   • resolved issue of infinitely searching nonexistent pages