Foursquare API List Update

[darrendaz]

TipsController#index:
@results = JSON.parse(resp.body)["response"]["tips"]["items"]

needs to be updated to the new API list response structure:
@results = JSON.parse(resp.body)["response"]["list"]["listItems"]["items"]

Also, no .env file is included or mentioned creating this error when submitting on the search page:
Missing access credentials. See https://developer.foursquare.com/docs/api/configuration/authentication for details.