Release patch version of Strudy - v2.1.2

Patch:
- Handle specs in crawl results that don't have a `nightly` property, following
a recent breaking change in browser-specs.

Dependencies also bumped to their latest versions.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "strudy",
-  "version": "2.1.1",
+  "version": "2.1.2",
   "description": "Web spec analysis tool that can process crawl reports created by Reffy.",
   "repository": {
     "type": "git",