Refactor contracts-* exports so none in test dir so npmignore works as intended

contracts/staking/src/constants.ts

@@ -0,0 +1,22 @@
+import { constants as testConstants } from '@0x/contracts-test-utils';
+import { BigNumber } from '@0x/utils';
+
+const TEN_DAYS = 10 * 24 * 60 * 60;
+const PPM = 10 ** 6;
+export const constants = {
+    TOKEN_MULTIPLIER: testConstants.DUMMY_TOKEN_DECIMALS,
+    INITIAL_POOL_ID: '0x0000000000000000000000000000000000000000000000000000000000000001',
+    SECOND_POOL_ID: '0x0000000000000000000000000000000000000000000000000000000000000002',
+    NIL_POOL_ID: '0x0000000000000000000000000000000000000000000000000000000000000000',
+    NIL_ADDRESS: '0x0000000000000000000000000000000000000000',
+    INITIAL_EPOCH: new BigNumber(1),
+    DEFAULT_PARAMS: {
+        epochDurationInSeconds: new BigNumber(TEN_DAYS),
+        rewardDelegatedStakeWeight: new BigNumber(PPM * 0.9),
+        minimumPoolStake: new BigNumber(10).pow(testConstants.DUMMY_TOKEN_DECIMALS).times(100),
+        cobbDouglasAlphaNumerator: new BigNumber(2),
+        cobbDouglasAlphaDenominator: new BigNumber(3),
+    },
+    PPM,
+    ONE_DAY_IN_SECONDS: 24 * 60 * 60,
+};