anchor.diff:  Get detailed information about a currency.
   GET /currencies/{isoCode}
   > Accept: application/json
  -> Api-Key: your API key
  +> Api_Key: your API key
   < 200
   < Content-Type: application/json
   < X-Rate-Limit-Limit: number of requests allowed in period
  
positive.code: Provides information about resources available through the API.
  OPTIONS /
  > Accept: application/json
  > Api-Key: your API key
  < 200
  < Content-Type: application/json
  < X-Rate-Limit-Limit: number of requests allowed in period
  
negative.code: Provides information about formatting a monetary amount according to its currency.
  OPTIONS /currencies/{isoCode}/format/{amount}
  > Accept: application/json
  > Api_Key: your API key
  < 200
  < Content-Type: application/json
  < X-Rate-Limit-Limit: number of requests allowed in period
  