Adds a canary test to fail Consul's test w/o porter.

testutil/porter_test.go

@@ -0,0 +1,13 @@
+package testutil
+
+import (
+	"testing"
+
+	"github.com/hashicorp/consul/test/porter"
+)
+
+func Test_PorterIsRunning(t *testing.T) {
+	if _, err := porter.RandomPorts(1); err != nil {
+		t.Fatalf("Porter must be running for Consul's unit tests")
+	}
+}