add now-mandatory metadata to toy course.xml

common/test/data/toy/course.xml

-<course name="Toy Course" graceperiod="1 day 5 hours 59 minutes 59 seconds" showanswer="always" rerandomize="never">
+<course name="Toy Course" org="edX" course="toy" graceperiod="1 day 5 hours 59 minutes 59 seconds" slug="2012_Fall" start="2015-07-17T12:00">
   <chapter name="Overview">
     <video name="Welcome" youtube="0.75:izygArpw-Qo,1.0:p2Q6BrNhdh8,1.25:1EeWXzPdhSA,1.50:rABDYkeK0x8"/>
     <videosequence format="Lecture Sequence" name="System Usage Sequence">