fix CI failures

contracts/staking/src/index.ts

@@ -45,7 +45,6 @@ export { StakingRevertErrors, FixedMathRevertErrors } from '@0x/utils';
 export { constants } from './constants';
 export {
     AggregatedStats,
-    AggregatedStatsByEpoch,
     StakeInfo,
     StakeStatus,
     StoredBalance,
@@ -57,6 +56,7 @@ export {
     GlobalStakeByStatus,
     StakingPool,
     PoolStats,
+    Numberish,
 } from './types';
 export {
     ContractArtifact,

contracts/staking/src/types.ts

@@ -231,3 +231,5 @@ export class AggregatedStats {
 export interface AggregatedStatsByEpoch {
     [epoch: string]: AggregatedStats;
 }
+
+export type Numberish = Numberish;

contracts/staking/test/unit_tests/lib_fixed_math_test.ts

@@ -7,7 +7,7 @@ import {
     toDecimal,
     toFixed,
 } from '@0x/contracts-test-utils';
-import { BigNumber, FixedMathRevertErrors } from '@0x/utils';
+import { BigNumber, FixedMathRevertErrors, hexUtils } from '@0x/utils';
 import { Decimal } from 'decimal.js';
 import * as _ from 'lodash';