set default balance when no one is there with simulator

lib/tests/test.js

@@ -72,6 +72,9 @@ class Test {
 
     if (this.simOptions.accounts) {
       this.simOptions.accounts = this.simOptions.accounts.map((account) => {
+        if (!account.hexBalance) {
+          account.hexBalance = '0x8AC7230489E80000'; // 10 ether
+        }
         return {balance: account.hexBalance, secretKey: account.privateKey};
       });
     }