Verify soruce setup code.

Author: mostlyobvious

lib/nanoc/github.rb

@@ -1,6 +1,6 @@
 require "nanoc"
 require "octokit"
-
+require "faraday/http_cache"
 
 module Nanoc
   module Github

test/source_test.rb

@@ -121,6 +121,10 @@ def test_use_access_token
           .to_return(status: 404)
         source_with_token.items
       end
+
+      def test_up
+        assert source_with_posts.up
+      end
     end
   end
 end