replace `is_group_milestone?` with `group_milestone?`

app/helpers/milestones_routing_helper.rb

 module MilestonesRoutingHelper
   def milestone_path(milestone, *args)
-    if milestone.is_group_milestone?
+    if milestone.group_milestone?
       group_milestone_path(milestone.group, milestone, *args)
     elsif milestone.project_milestone?
       project_milestone_path(milestone.project, milestone, *args)
@@ -8,7 +8,7 @@ module MilestonesRoutingHelper
   end
   def milestone_url(milestone, *args)
-    if milestone.is_group_milestone?
+    if milestone.group_milestone?
       group_milestone_url(milestone.group, milestone, *args)
     elsif milestone.project_milestone?
       project_milestone_url(milestone.project, milestone, *args)

app/models/concerns/milestoneish.rb

@@ -70,7 +70,7 @@ module Milestoneish
     due_date && due_date.past?
   end
-  def is_group_milestone?
+  def group_milestone?
     false
   end

app/models/milestone.rb

@@ -163,7 +163,7 @@ class Milestone < ActiveRecord::Base
   #   Milestone.first.to_reference(same_namespace_project)   # => "gitlab-ce%1"
   #
   def to_reference(from_project = nil, format: :iid, full: false)
-    return if is_group_milestone? && format != :name
+    return if group_milestone? && format != :name
     format_reference = milestone_format_reference(format)
     reference = "#{self.class.reference_prefix}#{format_reference}"
@@ -207,7 +207,7 @@ class Milestone < ActiveRecord::Base
     group || project
   end
-  def is_group_milestone?
+  def group_milestone?
     group_id.present?
   end

app/services/system_note_service.rb

@@ -142,7 +142,7 @@ module SystemNoteService
   #
   # Returns the created Note object
   def change_milestone(noteable, project, author, milestone)
-    format = milestone&.is_group_milestone? ? :name : :iid
+    format = milestone&.group_milestone? ? :name : :iid
     body = milestone.nil? ? 'removed milestone' : "changed milestone to #{milestone.to_reference(project, format: format)}"
     create_note(NoteSummary.new(noteable, project, author, body, action: 'milestone'))

app/views/shared/milestones/_milestone.html.haml

@@ -5,7 +5,7 @@
   .row
     .col-sm-6
       %strong= link_to truncate(milestone.title, length: 100), milestone_path
-      - if milestone.is_group_milestone?
+      - if milestone.group_milestone?
         %span - Group Milestone
       - else
         %span - Project Milestone
@@ -18,7 +18,7 @@
       ·
       = link_to pluralize(milestone.merge_requests.size, 'Merge Request'), merge_requests_path
     .col-sm-6= milestone_progress_bar(milestone)
-  - if milestone.is_a?(GlobalMilestone) || milestone.is_group_milestone?
+  - if milestone.is_a?(GlobalMilestone) || milestone.group_milestone?
     .row
       .col-sm-6
         - if milestone.legacy_group_milestone?
@@ -31,7 +31,7 @@
       - if @group
         .col-sm-6.milestone-actions
           - if can?(current_user, :admin_milestones, @group)
-            - if milestone.is_group_milestone?
+            - if milestone.group_milestone?
               = link_to edit_group_milestone_path(@group, milestone), class: "btn btn-xs btn-grouped" do
                 Edit
               \

app/views/shared/milestones/_top.html.haml

@@ -22,7 +22,7 @@
   - if group
     .pull-right
       - if can?(current_user, :admin_milestones, group)
-        - if milestone.is_group_milestone?
+        - if milestone.group_milestone?
           = link_to edit_group_milestone_path(group, milestone), class: "btn btn btn-grouped" do
             Edit
         - if milestone.active?
@@ -33,7 +33,7 @@
 .detail-page-description.milestone-detail
   %h2.title
     = markdown_field(milestone, :title)
-  - if @milestone.is_group_milestone? && @milestone.description.present?
+  - if @milestone.group_milestone? && @milestone.description.present?
     %div
       .description
         .wiki
@@ -67,7 +67,7 @@
               Open
           %td
             = ms.expires_at
-- elsif @milestone.is_group_milestone?
+- elsif @milestone.group_milestone?
   %br
   View
   = link_to 'Issues', issues_group_path(@group, milestone_title: milestone.title)