lntest: go easy on goroutines when polling

In high CPU usage scenarios such as our parallel itests, it seems that
some goroutines just don't get any CPU time before our test timeouts
expire. By polling 10 times less frequently, we hope to reduce the
overall number of goroutines that are spawned because of the RPC
requests within the polling code.

lntest/harness.go

@@ -223,7 +223,7 @@ func (n *NetworkHarness) SetUp(testCase string, lndArgs []string) error {
 	// Now block until both wallets have fully synced up.
 	expectedBalance := int64(btcutil.SatoshiPerBitcoin * 10)
 	balReq := &lnrpc.WalletBalanceRequest{}
-	balanceTicker := time.NewTicker(time.Millisecond * 50)
+	balanceTicker := time.NewTicker(time.Millisecond * 200)
 	defer balanceTicker.Stop()
 	balanceTimeout := time.After(time.Second * 30)
 out:

lntest/wait/wait.go

@@ -11,7 +11,7 @@ import (
 // several running lnd nodes. This function gives callers a way to assert that
 // some property is upheld within a particular time frame.
 func Predicate(pred func() bool, timeout time.Duration) error {
-	const pollInterval = 20 * time.Millisecond
+	const pollInterval = 200 * time.Millisecond
 
 	exitTimer := time.After(timeout)
 	for {