Re-enable Stanford OC test

test/tests.json

@@ -76,8 +76,7 @@
     "name": "StanfordOpenClassroom",
     "md5":  "544a9468546059d4e80d76265b0443b8",
     "url":  "http://openclassroom.stanford.edu/MainFolder/VideoPage.php?course=PracticalUnix&video=intro-environment&speed=100",
-    "file":  "PracticalUnix_intro-environment.mp4",
-    "skip": "Currently offline"
+    "file":  "PracticalUnix_intro-environment.mp4"
   },
   {
     "name": "XNXX",