Updated the asset-proxy tests to use RichErrors

packages/utils/src/safe_math_revert_errors.ts

@@ -1,5 +1,6 @@
 import { BigNumber } from './configured_bignumber';
 import { RevertError } from './revert_error';
+import * as _ from 'lodash';
 
 // tslint:disable:max-classes-per-file
 
@@ -24,7 +25,7 @@ export class Uint256UnderflowError extends RevertError {
 const types = [
     Uint256OverflowError,
     Uint256UnderflowError,
-]
+];
 
 // Register the types we've defined.
 for (const type of types) {