fix: erc20Dividend bug and example

Author: Victor Wiebe

examples/erc20Dividend.ts

@@ -160,7 +160,7 @@ window.addEventListener('load', async () => {
     token: await polymathAPI.polyToken.address(),
     expiry: new Date(2035, 2),
     maturity: new Date(2018, 1),
-    checkpointId: 1,
+    checkpointId: 2,
     excluded: [randomInvestors[0], randomInvestors[1]],
   });
 
@@ -179,7 +179,7 @@ window.addEventListener('load', async () => {
     token: await polymathAPI.polyToken.address(),
     expiry: new Date(2035, 2),
     maturity: new Date(2018, 1),
-    checkpointId: 2,
+    checkpointId: 3,
   });
 
   console.log('4 types of erc20 dividends created');

examples/etherDividend.ts

@@ -159,7 +159,7 @@ window.addEventListener('load', async () => {
     value: new BigNumber(1),
     expiry: new Date(2035, 2),
     maturity: new Date(2018, 1),
-    checkpointId: 1,
+    checkpointId: 2,
     excluded: [randomInvestors[0], randomInvestors[1]],
   });
 
@@ -176,7 +176,7 @@ window.addEventListener('load', async () => {
     value: new BigNumber(1),
     expiry: new Date(2035, 2),
     maturity: new Date(2018, 1),
-    checkpointId: 2,
+    checkpointId: 3,
   });
 
   console.log('4 types of ether dividends created');

src/contract_wrappers/modules/checkpoint/dividend_checkpoint_wrapper.ts

@@ -504,7 +504,7 @@ export default abstract class DividendCheckpointWrapper extends ModuleWrapper {
 
     if (checkpointId) {
       const currentCheckpointId = await stContract.currentCheckpointId.callAsync();
-      assert.assert(checkpointId < currentCheckpointId.toNumber(), 'Invalid checkpoint');
+      assert.assert(checkpointId <= currentCheckpointId.toNumber(), 'Invalid checkpoint');
     }
 
     const callerAddress = await this.getCallerAddress(txData);