Adds feature and updates testing API

[10thfloor]

The aim of this work is to simplify working with Cadence in testing scenarios. Building on the great foundation laid by @MaxStalker

TODO:

• Example tests
• Arguments to tx and contract init() functions

Highlights of this PR:
Loading Cadence files. Once configured, flow-js-testing can load Cadence files by name

const NFTContract = await contract("NonFungibleToken");
const FTContract = await contract("FungibleToken");
const MarketplaceContract = await contract("MarketPlace);

const tx1 = await tx("tx_01_check_nft");
const tx2 = await tx("tx_02_configure_user_account");

const script1 = await script("check_balance")

Simple API to create accounts for testing purposes. Users can create a Flow account, and alias it for lookup later. In this case, If an account named "Bob" already exists, it returns the account.

let Bob = account("Bob")
let Alice = account("Bob")

Explicit functions for updating protocol state

Bob = await F.createAccount(Bob) // Bob is now a 'DeployedAccount' object

const DeployedNFTContract = await F.deployContract(Bob, NFTContract)
const DeployedFTContract = await F.deployContract(Alice, FTContract)
const DeployedMarketplaceContract = await F.deployContract(Alice, MarketplaceContract)

const txResult = await F.sendTx(tx1)

F.addBalance(Bob, 200);
F.addBalance(Alice, 200)

Easily replace imports (Done before execution / deployment)

tx1.importing({
   NonFungibleToken: DeployedNFTContract.address,
});

tx1.replace({
      "getAccount(0x01)": `getAccount(${Bob.address})`, // can also use regex replace
});

tx1.signers(Bob.address);

script1.importing({
   FungibleToken: DeployedFTContract.address
})

MarketplaceContract.importing({
  NonFungibleToken: DeployedNFTContract.address,
  FungibleToken: DeployedFTContract.address
})

[ericc572]

any updates as to when this will be merged? we are starting to test soon

[10thfloor]

Closing because these changes have been superseded by: #16 - #22 et. al.