normalize_positions: Normalize positions by allowed counts
In zamorarr/coach: Lineup optimization for daily fantasy sports

Will replace positions with wildcard if their count exceeds the max allowed. This is commonly used to set a player to a utility or flex position.

normalize_positions(pos, pos_max, wildcard)

normalize_dk_nfl(pos)

normalize_dk_nba(pos)

normalize_dk_nhl(pos)

normalize_fd_nfl(pos)

normalize_fd_mlb(pos)

normalize_fd_nascar(pos)

normalize_fdr_nba(pos)

`pos`	a character vector of existing positions
`pos_max`	a named numeric vector giving the max allowed players at that position
`wildcard`	a string specifying what to replace positions with

## Not run: 
 pos <- c("P", "1B", "1B", "2B", "3B", "SS", "OF", "OF", "OF")
 pos_max <- c("P" = 1, "1B" = 1, "2B" = 1, "3B" = 1, "SS" = 1, "OF" = 3)
 wildcard <- "UTIL"

 normalize_positions(pos, pos_max, wildcard)

## End(Not run)