circle.yml in kickster-1.5.0

- old
+ new

@@ -1,12 +1,12 @@
 machine:
   ruby:
-    version: 2.3.1
+    version: 2.4.0
 
 dependencies:
   pre:
     - ./bin/setup
 
 test:
   post:
     - bundle exec jekyll build
-    - bundle exec htmlproofer ./_site --only-4xx --allow-hash-href
+    - bundle exec htmlproofer ./_site --only-4xx --allow-hash-href --assume-extension --check-opengraph