Add Swarm limits

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

gateway/tests/resources_test.go

@@ -0,0 +1,20 @@
+package tests
+
+import (
+	"testing"
+
+	"github.com/openfaas/faas/gateway/handlers"
+)
+
+func Test_ParseMemory(t *testing.T) {
+	value := "512 m"
+
+	val, err := handlers.ParseMemory(value)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if val != 1024*1024*512 {
+		t.Errorf("want: %d got: %d", 1024, val)
+	}
+}