lnwire: replace all wire msg tests with a single property-based test

This commit does away with all the old manual message equality tests
and replace it with a single property-based test that uses the
testing/quick package. This test uses a single scenario which MUST hold
for all the messages type and all possible messages generated for those
types. As a result we are able to do away with all the prior manually
generated test data as the fuzzer to scan the input space looking for a
message that violates the scenario.

lnwire/update_fulfill_htlc_test.go

@@ -1,30 +0,0 @@
-package lnwire
-
-import (
-	"bytes"
-	"reflect"
-	"testing"
-)
-
-func TestUpdateFufillHTLCEncodeDecode(t *testing.T) {
-	// First create a new HTLCSR message.
-	settleReq := NewUpdateFufillHTLC(ChannelID(revHash), 23, revHash)
-
-	// Next encode the HTLCSR message into an empty bytes buffer.
-	var b bytes.Buffer
-	if err := settleReq.Encode(&b, 0); err != nil {
-		t.Fatalf("unable to encode UpdateFufillHTLC: %v", err)
-	}
-
-	// Deserialize the encoded SFOP message into a new empty struct.
-	settleReq2 := &UpdateFufillHTLC{}
-	if err := settleReq2.Decode(&b, 0); err != nil {
-		t.Fatalf("unable to decode UpdateFufillHTLC: %v", err)
-	}
-
-	// Assert equality of the two instances.
-	if !reflect.DeepEqual(settleReq, settleReq2) {
-		t.Fatalf("encode/decode error messages don't match %#v vs %#v",
-			settleReq, settleReq2)
-	}
-}