Might be missing some airports

[sselao]

I noticed IATA:LAS (McCarran International Airport, Las Vegas) is missing. There may be other ones too but that's the only one I've noticed so far.

[raybellis]

IATA:SEL is missing (info at http://airport-codes.wanderbat.com/l/5564/Seoul-South-Korea-Kimpo-International-Seoul-Metropolitan-Area)

[raybellis]

IATA:PAO (Palo Alto) too.

[jbrooksuk]

Feel free to add them in :)

[joeframbach]

Missing STS as well https://en.wikipedia.org/wiki/Charles_M._Schulz%E2%80%93Sonoma_County_Airport

[jbrooksuk]

Accepting Pull Requests :)