Remove test-helpers from build (#459)

The test helpers file is showing up in the published package when it
should not be. This commit moves it to a directory that is automatically
excluded by the TypeScript configuration.

Author: mcmire

jest.config.js

@@ -8,8 +8,8 @@ module.exports = {
     global: {
       branches: 75.52,
       functions: 92.5,
-      lines: 92.64,
-      statements: 92.65,
+      lines: 92.52,
+      statements: 92.51,
     },
   },
   moduleFileExtensions: ['js', 'json', 'jsx', 'ts', 'tsx', 'node'],

src/SmartTransactionsController.test.ts

@@ -30,11 +30,11 @@ import type {
   SmartTransactionsControllerActions,
   SmartTransactionsControllerEvents,
 } from './SmartTransactionsController';
-import { advanceTime, flushPromises, getFakeProvider } from './test-helpers';
 import type { SmartTransaction, UnsignedTransaction, Hex } from './types';
 import { SmartTransactionStatuses } from './types';
 import * as utils from './utils';
 import packageJson from '../package.json';
+import { advanceTime, flushPromises, getFakeProvider } from '../tests/helpers';
 
 jest.mock('@ethersproject/bytes', () => ({
   ...jest.requireActual('@ethersproject/bytes'),