chore(package): update scratch-storage to version 1.2.0

package.json

@@ -103,7 +103,7 @@
     "scratch-l10n": "3.0.20181031234255",
     "scratch-paint": "0.2.0-prerelease.20181029151725",
     "scratch-render": "0.1.0-prerelease.20181029125804",
-    "scratch-storage": "1.1.0",
+    "scratch-storage": "1.2.0",
     "scratch-svg-renderer": "0.2.0-prerelease.20181024192149",
     "scratch-vm": "0.2.0-prerelease.20181030160328",
     "selenium-webdriver": "3.6.0",