v1.35.0

• Introduce Heroku Pipelines support
• Update to Ruby 2.3.0
• Heroku commands run on staging by default
• Git ignore .env.local instead of .env
• Add ability to use byebug navigation commands inside of Pry using the
  pry-byebug gem
• Remove i18n-tasks from generated Gemfile
• Accessibility: Add lang attribute to html element in layout