message: Refactor: provider methods setup
diff: import { providers } from 'ethers';
  -const colonyWallet = {
  - etherscan: (network: string = 'homested'): void =>
  - new providers.EtherscanProvider(network),
  - infura: (network: string = 'homested'): void =>
  - new providers.InfuraProvider(network),
  - metamask: (network: string = 'homested'): void => {
  +const defaultNetwork = 'homestead';
  +
  +const etherscan = (network: string = defaultNetwork): void => {
  + const provider = new providers.EtherscanProvider(network);
  + return provider;
  +};
  +
  +const infura = (network: string = defaultNetwork): void => {
  + const provider = new providers.InfuraProvider(network);
  + return provider;
  +};
  +
  +const metamask = (network: string = defaultNetwork): void => {
  if (window.web3 && window.web3.currentProvider) {
  return new providers.Web3Provider(window.web3.currentProvider, network);
  }
  return undefined;
  - },
  +};
  +
  +const colonyWallet = {
  + etherscan,
  + infura,
  + metamask,
  };
  export default colonyWallet;
  