Account API and Australian Exchange

A number of additions

• bf_account returns an environment with methods for minimal access to the Accounts APING, for returning data about account, funds, details, statements, and allows funds to be transferred. The account statement can hopefully be plotted, showing profit/loss over time

acc <- bf_account(usr = Sys.getenv("BETFAIR_USR"), 
                  pwd = Sys.getenv("BETFAIR_PWD"), 
                  key = Sys.getenv("BETFAIR_KEY"))
statement <- acc$statement()
plot(statement)

• betfair now takes an additional argument, called dom, which sets the exchange domain, default is "uk", change to "aus" for Australian exchange

bf <- betfair(usr = Sys.getenv("BETFAIR_USR"), 
              pwd = Sys.getenv("BETFAIR_PWD"), 
              key = Sys.getenv("BETFAIR_KEY"),
              dom = "aus")

• betfair includes method (account) which calls bf_account and returns account environment, be careful not to share this!