Fix quotes around remote_theme in config

Author: asanka-code

_config.yml

@@ -32,7 +32,7 @@ github_username:  jekyll
 
 # Build settings
 # theme: minima 
-remote_theme: zerostaticthemes/jekyll-serif-theme 
+remote_theme: "zerostaticthemes/jekyll-serif-theme" 
 plugins:
   - jekyll-remote-theme # add this line to the plugins list if you already have one
   - jekyll-feed