fix typos in JSON that caused travis build to fail

Author: McEileen

exercises/raindrops/canonical-data.json

@@ -23,7 +23,7 @@
       {
         "number" : 8,
         "expected": "8"
-      }
+      },
       {
          "number" : 9,
          "expected": "Pling"
@@ -51,7 +51,7 @@
       {
          "number" : 27,
          "expected": "Pling"
-      }
+      },
       {
          "number" : 35,
          "expected": "PlangPlong"