Add the description to the "new issue" and "new merge request" emails

Previously the content of the issue or merge request was missing from
the email.

app/views/notify/new_issue_email.html.haml

-%p
-  New Issue was created.
-%p
-  Author: #{@issue.author_name}
+-if @issue.description
+  = markdown(@issue.description)
+
+- if @issue.assignee_id.present?
   %p
     Assignee: #{@issue.assignee_name}

app/views/notify/new_merge_request_email.html.haml

@@ -2,6 +2,10 @@
   = "New Merge Request ##{@merge_request.iid}"
 %p
   != merge_path_description(@merge_request, '→')
+
+- if @merge_request.assignee_id.present?
   %p
     Assignee: #{@merge_request.author_name} → #{@merge_request.assignee_name}
+-if @merge_request.description
+  = markdown(@merge_request.description)

spec/mailers/notify_spec.rb

@@ -147,6 +147,7 @@ describe Notify do
       context 'for issues' do
         let(:issue) { create(:issue, author: current_user, assignee: assignee, project: project) }
+        let(:issue_with_description) { create(:issue, author: current_user, assignee: assignee, project: project, description: Faker::Lorem.sentence) }
         describe 'that are new' do
           subject { Notify.new_issue_email(issue.assignee_id, issue.id) }
@@ -162,6 +163,14 @@ describe Notify do
           end
         end
+        describe 'that are new with a description' do
+          subject { Notify.new_issue_email(issue_with_description.assignee_id, issue_with_description.id) }
+
+          it 'contains the description' do
+            should have_body_text /#{issue_with_description.description}/
+          end
+        end
+
         describe 'that have been reassigned' do
           subject { Notify.reassigned_issue_email(recipient.id, issue.id, previous_assignee.id, current_user) }
@@ -221,6 +230,7 @@ describe Notify do
       context 'for merge requests' do
         let(:merge_request) { create(:merge_request, author: current_user, assignee: assignee, source_project: project, target_project: project) }
+        let(:merge_request_with_description) { create(:merge_request, author: current_user, assignee: assignee, source_project: project, target_project: project, description: Faker::Lorem.sentence) }
         describe 'that are new' do
           subject { Notify.new_merge_request_email(merge_request.assignee_id, merge_request.id) }
@@ -244,6 +254,14 @@ describe Notify do
           end
         end
+        describe 'that are new with a description' do
+          subject { Notify.new_merge_request_email(merge_request_with_description.assignee_id, merge_request_with_description.id) }
+
+          it 'contains the description' do
+            should have_body_text /#{merge_request_with_description.description}/
+          end
+        end
+
         describe 'that are reassigned' do
           subject { Notify.reassigned_merge_request_email(recipient.id, merge_request.id, previous_assignee.id, current_user.id) }