test: speed up integration test harness initialization

This commit speeds up the integration test initialization by launching
the processes of the two seeder nodes concurrently rather than
serially.

Additionally, the harness will now block until the wallets of both the
seeder nodes are fully synced up.

networkharness.go

@@ -11,6 +11,7 @@ import (
 	"path/filepath"
 	"runtime"
 	"strconv"
+	"sync"
 	"time"
 
 	"golang.org/x/net/context"
@@ -284,20 +285,40 @@ func (n *networkHarness) SetUp() error {
 
 	// Start the initial seeder nodes within the test network, then connect
 	// their respective RPC clients.
+	var wg sync.WaitGroup
+	errChan := make(chan error, 2)
+	wg.Add(2)
+	go func() {
 		var err error
-	if err := n.aliceNode.start(); err != nil {
-		return err
-	}
-	if err := n.bobNode.start(); err != nil {
-		return err
+		defer wg.Done()
+		if err = n.aliceNode.start(); err != nil {
+			errChan <- err
+			return
 		}
 		n.AliceClient, err = initRpcClient(n.aliceNode.rpcAddr)
 		if err != nil {
-		return nil
+			errChan <- err
+			return
+		}
+	}()
+	go func() {
+		var err error
+		defer wg.Done()
+		if err = n.bobNode.start(); err != nil {
+			errChan <- err
+			return
 		}
 		n.BobClient, err = initRpcClient(n.bobNode.rpcAddr)
 		if err != nil {
-		return nil
+			errChan <- err
+			return
+		}
+	}()
+	wg.Wait()
+	select {
+	case err := <-errChan:
+		return err
+	default:
 	}
 
 	// Load up the wallets of the seeder nodes with 10 outputs of 1 BTC
@@ -351,6 +372,30 @@ func (n *networkHarness) SetUp() error {
 		return err
 	}
 
+	// Now block until both wallets have fully synced up.
+	expectedBalance := btcutil.Amount(btcutil.SatoshiPerBitcoin * 10).ToBTC()
+	balReq := &lnrpc.WalletBalanceRequest{}
+	balanceTicker := time.Tick(time.Millisecond * 100)
+out:
+	for {
+		select {
+		case <-balanceTicker:
+			aliceResp, err := n.AliceClient.WalletBalance(ctxb, balReq)
+			if err != nil {
+				return err
+			}
+			bobResp, err := n.BobClient.WalletBalance(ctxb, balReq)
+			if err != nil {
+				return err
+			}
+
+			if aliceResp.Balance == expectedBalance &&
+				bobResp.Balance == expectedBalance {
+				break out
+			}
+		}
+	}
+
 	return nil
 }
 
@@ -371,7 +416,7 @@ func initRpcClient(serverAddr string) (lnrpc.LightningClient, error) {
 	opts := []grpc.DialOption{
 		grpc.WithInsecure(),
 		grpc.WithBlock(),
-		grpc.WithTimeout(time.Second * 10),
+		grpc.WithTimeout(time.Second * 20),
 	}
 	conn, err := grpc.Dial(serverAddr, opts...)
 	if err != nil {