message: Expose CeloCoin from
  Other libraries need to be able to compare statics `Coin` objects with
  the type of coin that they are an instance of. This commit exposes
  `CeloCoin` so that this functionality is available
  Ticket:
diff: @@ -4,5 +4,5 @@ export * from './networks';
  export * from './errors';
  export { OfcCoin } from './ofc';
  export { UtxoCoin } from './utxo';
  -export { AccountCoin, Erc20Coin, StellarCoin } from './account';
  +export { AccountCoin, CeloCoin, Erc20Coin, StellarCoin } from './account';
  export { CoinMap } from './map';
  