[TESTS] Adding some tests.

AlexandreTests.ipynb

 {
  "metadata": {
   "name": "",
-  "signature": "sha256:077d042952acacfaf160a1c3655fadac325f85beb77437b97247043bf738b3a5"
+  "signature": "sha256:5d4e47f4a449ee5576528c319c4ba604e524bdb529ffe836bac49e42b60dd575"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -20,7 +20,27 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 15
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "Language.objects.get(iso2='fr')"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "metadata": {},
+       "output_type": "pyout",
+       "prompt_number": 3,
+       "text": [
+        "<Language: French>"
+       ]
+      }
+     ],
+     "prompt_number": 3
     },
     {
      "cell_type": "code",