change box handling and update boxes

 {
-  "name": "centos/7",
+  "name": "ghopp/centos7",
   "description": "The latest centos/7 LXD image.",
   "versions": [
     {
-      "version": "0.0.1",
+      "version": "0.0.2",
       "providers": [
         {
           "name": "lxd",
-          "url": "file:///home/hopp/projects/vagrant/test/centos_001_lxd.box",
+          "url": "https://github.com/georghopp/vagrant-lxd/raw/master/example_boxes/centos_002_lxd.box",
           "checksum_type": "sha1",
-          "checksum": "52c6717974bc76ecb9591e55d30baf90be9c68e4"
+          "checksum": "9b9e8e343c72b020ff21641bc18b6512df936047"
         }
       ]
     }

 {
   "provider": "lxd",
+  "image": "centos/7",
   "bootstrap": {
     "hostname": {
       "exec": [

 {
-  "name": "lxd/gentoo",
+  "name": "ghopp/gentoo",
   "description": "The latest gentoo LXD image.",
   "versions": [
     {
-      "version": "0.0.1",
+      "version": "0.0.2",
       "providers": [
         {
           "name": "lxd",
-          "url": "file:///home/hopp/projects/vagrant/vagrant-lxd/gentoo_001_lxd.box",
+          "url": "https://github.com/georghopp/vagrant-lxd/raw/master/example_boxes/gentoo_002_lxd.box",
           "checksum_type": "sha1",
-          "checksum": "279b73b0a0f51368376a89283c842c5b474f9274"
+          "checksum": "32b92c1c5121b13cedb051739066a1f098666b17"
         }
       ]
     }

 {
   "provider": "lxd",
+  "image": "gentoo",
   "bootstrap": {
     "hostname": {
       "exec": [

 {
-  "name": "debian/sid",
+  "name": "ghopp/sid",
   "description": "The latest debian/sid LXD image.",
   "versions": [
     {
-      "version": "0.0.1",
+      "version": "0.0.2",
       "providers": [
         {
           "name": "lxd",
-          "url": "file:///home/hopp/projects/vagrant/test/sid_001_lxd.box",
+          "url": "https://github.com/georghopp/vagrant-lxd/raw/master/example_boxes/sid_002_lxd.box",
           "checksum_type": "sha1",
-          "checksum": "21d7376327acdb7f36aa25ed89039248c6562415"
+          "checksum": "fc23c3fe375bd3383f076625f6904602482a9c34"
         }
       ]
     }

 {
   "provider": "lxd",
+  "image": "debian/sid",
   "bootstrap": {
     "hostname": {
       "exec": [

@@ -90,7 +90,7 @@ module VagrantPlugins
       end
 
       def image
-        @machine.box.name if @machine.box
+        @machine.box.metadata["image"] if @machine.box
       end
 
       def image?