directory structure change to work with glide

glide has its own requirements. My previous workaround caused me some
code checkin errors. Need to fix this.

weed/topology/configuration_test.go

@@ -0,0 +1,42 @@
+package topology
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestLoadConfiguration(t *testing.T) {
+
+	confContent := `
+
+<?xml version="1.0" encoding="UTF-8" ?>
+<Configuration>
+  <Topology>
+    <DataCenter name="dc1">
+      <Rack name="rack1">
+        <Ip>192.168.1.1</Ip>
+      </Rack>
+    </DataCenter>
+    <DataCenter name="dc2">
+      <Rack name="rack1">
+        <Ip>192.168.1.2</Ip>
+      </Rack>
+      <Rack name="rack2">
+        <Ip>192.168.1.3</Ip>
+        <Ip>192.168.1.4</Ip>
+      </Rack>
+    </DataCenter>
+  </Topology>
+</Configuration>
+`
+	c, err := NewConfiguration([]byte(confContent))
+
+	fmt.Printf("%s\n", c)
+	if err != nil {
+		t.Fatalf("unmarshal error:%v", err)
+	}
+
+	if len(c.Topo.DataCenters) <= 0 || c.Topo.DataCenters[0].Name != "dc1" {
+		t.Fatalf("unmarshal error:%s", c)
+	}
+}