fix return value of token transfer

src/keeper/contracts/ContractBase.ts

@@ -90,11 +90,10 @@ export abstract class ContractBase extends Instantiable {
             const estimatedGas = await methodInstance.estimateGas(args, {
                 from
             })
-            const tx = methodInstance.send({
+            return methodInstance.send({
                 from,
                 gas: estimatedGas
             })
-            return tx
         } catch (err) {
             const mappedArgs = this.searchMethod(name, args).inputs.map((input, i) => {
                 return {

src/keeper/contracts/Token.ts

@@ -1,4 +1,5 @@
 import BigNumber from 'bignumber.js'
+import { TransactionReceipt } from 'web3-core'
 import ContractBase from './ContractBase'
 import { InstantiableConfig } from '../../Instantiable.abstract'
 
@@ -24,6 +25,8 @@ export default class OceanToken extends ContractBase {
     }
 
     public async transfer(to: string, amount: number, from: string) {
-        return this.send('transfer', from, [to, amount])
+        return this.send('transfer', from, [to, amount]).then(
+            (result: TransactionReceipt) => result.transactionHash
+        )
     }
 }