build_url: Build URL to scrape player season stat pages
Description
This is a sub-function for the get_season_rosters function.
Usage
build_url(position, season, page = 1, type)
Arguments
position
(character string) Specifies a player position page for the URL
season
4-digit year associated with a given NFL season
page
1-digit page number to look into
type
A three character string specifying the season type: pre, post, or reg