Update to monaco-editor-core 0.5.3 (without legacy JSON mode)

package.json

@@ -18,7 +18,7 @@
     "event-stream": "^3.3.2",
     "gulp": "^3.9.1",
     "http-server": "^0.9.0",
-    "monaco-editor-core": "0.5.2",
+    "monaco-editor-core": "0.5.3",
     "monaco-languages": "0.3.0",
     "monaco-typescript": "0.5.0",
     "monaco-css": "1.1.0",