Only show "Read more" if excerpt is not full article
Update to latest version of sitemap generator plugin

Fixes #4
Update category generator plugin to latest version
Use image-tag instead of picture-tag

This is to support other browsers besides chrome. When html5 picture
element becomes more widely supported I should switch back.

Fixes #3
Remove rb-gsl from the :default Gemfile group so that it is not required

bundle install --without gsl
Merge remote-tracking branch 'adamwalz.net/master'