Update devDependencies and gems.

Downgrade bundlesize until they make brotli optional since it doesn't work with node.js 10.x yet.

So, babel, qunit/karma-qunit and bundle-size aren't the latest versions.

build/.htmllintrc

@@ -5,9 +5,9 @@
   "attr-no-unsafe-char": true,
   "attr-quote-style": "double",
   "attr-req-value": true,
-  "attr-validate": true,
+  "attr-validate": false,
   "class-no-dup": true,
-  "class-style": "dash",
+  "class-style": "none",
   "doctype-first": true,
   "doctype-html5": true,
   "fig-req-figcaption": false,
@@ -19,7 +19,7 @@
   "html-valid-content-model": false,
   "id-class-ignore-regex": "(onclick|content|[a-z]+([A-Z][a-z])+)",
   "id-class-no-ad": true,
-  "id-class-style": "dash",
+  "id-class-style": false,
   "id-no-dup": true,
   "img-req-alt": "allownull",
   "img-req-src": false,
@@ -29,12 +29,13 @@
   "input-req-label": false,
   "label-req-for": true,
   "lang-style": "case",
+  "line-no-trailing-whitespace": false,
   "line-end-style": "lf",
   "spec-char-escape": false,
   "table-req-header": false,
   "tag-bans": ["b", "i"],
   "tag-close": true,
-  "tagname-lowercase": true,
+  "tag-name-lowercase": true,
   "tag-name-match": true,
   "tag-self-close": false,
   "text-ignore-regex": false,