feat(messages): render markdown in message body

uses redcarpet gem to render markdown to html. Also a html email template
is added.

Gemfile

@@ -128,4 +128,4 @@ group :test do
   gem 'hashie', '~> 3.4.6', require: false # https://github.com/westfieldlabs/apivore/issues/114
 end
 
-gem "redcarpet"
+gem "redcarpet", "~> 3.6"

Gemfile.lock

@@ -653,7 +653,7 @@ DEPENDENCIES
   rails_tokeninput
   ransack
   recurring_select!
-  redcarpet
+  redcarpet (~> 3.6)
   resque
   roo
   roo-xls

app/helpers/application_helper.rb

@@ -263,26 +263,4 @@ module ApplicationHelper
       stylesheet_link_tag foodcoop_css_path, media: 'all'
     end
   end
-
-  # renders html from markdown input
-  def markdown(text)
-    options = {
-        filter_html: true,
-        hard_wrap: true,
-        link_attributes: { rel: 'nofollow', target: "_blank" },
-        fenced_code_blocks: true
-      }
-      extensions = {
-        autolink: true,
-        superscript: true,
-        disable_indented_code_blocks: true,
-        tables: true,
-        strikethrough: true,
-        footnotes: true
-    }
-
-    renderer = ::Redcarpet::Render::HTML.new(options)
-    markdown = ::Redcarpet::Markdown.new(renderer, extensions)
-    markdown.render(text).html_safe
-  end
 end

plugins/messages/app/models/message.rb

@@ -132,6 +132,11 @@ class Message < ApplicationRecord
     user.role_admin?
   end
 
+  def render_markdown
+    markdown = Redcarpet::Markdown.new(Redcarpet::Render::HTML, autolink: true, tables: true, strikethrough: true, footnotes: true)
+    return markdown.render(body)
+  end
+
   private
 
   def create_salt

plugins/messages/app/views/messages/show.haml

@@ -33,7 +33,7 @@
         - if @message.can_toggle_private?(current_user)
           = link_to t('.change_visibility'), toggle_private_message_path(@message), method: :post, class: 'btn btn-mini'
   %hr/
-  = markdown(@message.body)
+  = raw @message.render_markdown
   %hr/
   %p
     = link_to t('.reply'), new_message_path(:message => {:reply_to => @message.id}), class: 'btn'

plugins/messages/app/views/messages/thread.haml

@@ -9,7 +9,7 @@
     .panel-heading
       %b= h(message.sender_name)
       = format_time(message.created_at)
-    .panel-body= markdown(message.body)
+    .panel-body= simple_format(h(message.body))
 
 %p
   = link_to t('.reply'), new_message_path(:message => {:reply_to => thread_message.id}), class: 'btn'

plugins/messages/app/views/messages_mailer/foodsoft_message.html.haml

@@ -1,4 +1,4 @@
-= markdown(@message.body)
+= raw @message.render_markdown
 %hr/
 %pre
   - if @message.group