Test setup helper added (#1482)

* signing prefix added

* Minor improvement

* Tests changed

* Successfully tested

* Minor improvements

* Minor improvements

* Revert "Dangling commas are now required. (#1359)"

This reverts commit a6889776f4.

* updates

* fixes #1404

* approve failing test

* suggested changes done

* ISafeERC20 removed

* conflict fixes

* fixes #1205

* minor change

* suggested changes

* reviewed changes

* final update

test/utils/Arrays.test.js

@@ -1,10 +1,6 @@
 const ArraysImpl = artifacts.require('ArraysImpl');
 
-const BigNumber = web3.BigNumber;
-
-require('chai')
-  .use(require('chai-bignumber')(BigNumber))
-  .should();
+require('../helpers/setup');
 
 contract('Arrays', function () {
   context('Even number of elements', function () {