rpctest: ensure the main harness rejects non-standard transactions

This commit modifies the current set of integration tests to ensure
that that the main harness always rejects non-standard transactions.

With this in place, even though we’re using simnet parameters, we
ensure that transaction acceptance/validation is identical to that of
main net.

rpcserver_test.go

@@ -101,7 +101,12 @@ var primaryHarness *rpctest.Harness
 
 func TestMain(m *testing.M) {
 	var err error
-	primaryHarness, err = rpctest.New(&chaincfg.SimNetParams, nil, nil)
+
+	// In order to properly test scenarios on as if we were on mainnet,
+	// ensure that non-standard transactions aren't accepted into the
+	// mempool or relayed.
+	btcdCfg := []string{"--rejectnonstd"}
+	primaryHarness, err = rpctest.New(&chaincfg.SimNetParams, nil, btcdCfg)
 	if err != nil {
 		fmt.Println("unable to create primary harness: ", err)
 		os.Exit(1)