Fix broken codelab dates.

Author: robdodson

src/site/content/en/fast/codelab-preload-critical-assets/index.md

@@ -7,8 +7,7 @@ description: |
   and prefetching resources.
 web_lighthouse:
   - uses-rel-preload
-web_updated_on: 2018-12-06
-web_published_on: 2018-11-05
+date: 2018-11-05
 glitch: preload-critical-assets
 ---
 

src/site/content/en/fast/codelab-preload-web-fonts/index.md

@@ -5,8 +5,7 @@ author: gmimani
 description: |
   In this codelab, learn how to improve the performance of a page by preloading
   web fonts.
-web_updated_on: 2018-12-06
-web_published_on: 2018-11-05
+date: 2018-11-05
 glitch: web-dev-preload-webfont
 ---
 

src/site/content/en/fast/codelab-text-compression/index.md

@@ -6,8 +6,7 @@ description: |
   In this codelab, learn how both minifying and compressing the JavaScript
   bundle for an application improves page performance by reducing the app's
   request size.
-web_updated_on: 2018-12-06
-web_published_on: 2018-11-05
+date: 2018-11-05
 glitch: fav-kitties-compress-starter
 related_post: reduce-network-payloads-using-text-compression
 ---