Update _form.html.erb
Update _form.html.erb

Add html: { class: 'form-horizontal' }
PowerCodeGirls/RubyGameDev.com,RailsGEnthusiasts/RubyGameDev.com,ruby-rcade/RubyGameDev.com,RailsGEnthusiasts/RubyGameDev.com,RailsGEnthusiasts/RubyGameDev.com,ruby-rcade/RubyGameDev.com,PowerCodeGirls/RubyGameDev.com,PowerCodeGirls/RubyGameDev.com,ruby-rcade/RubyGameDev.com