Devise 3.5.x deprecates `confirm!` in favor of `confirm`

app/controllers/admin/users_controller.rb

@@ -56,7 +56,7 @@ class Admin::UsersController < Admin::ApplicationController
   end
 
   def confirm
-    if user.confirm!
+    if user.confirm
       redirect_to :back, notice: "Successfully confirmed"
     else
       redirect_to :back, alert: "Error occurred. User was not confirmed"

db/fixtures/production/001_admin.rb

@@ -19,7 +19,7 @@ admin = User.create(
 admin.projects_limit = 10000
 admin.admin = true
 admin.save!
-admin.confirm!
+admin.confirm
 
 if admin.valid?
 puts %Q[

spec/mailers/notify_spec.rb

@@ -712,7 +712,7 @@ describe Notify do
 
         before do
           user.update_attribute(:email, "user@company.com")
-          user.confirm!
+          user.confirm
         end
 
         it "is sent from the committer email" do
@@ -730,7 +730,7 @@ describe Notify do
 
         before do
           user.update_attribute(:email, "user@something.company.com")
-          user.confirm!
+          user.confirm
         end
 
         it "is sent from the default email" do
@@ -748,7 +748,7 @@ describe Notify do
 
         before do
           user.update_attribute(:email, "user@mpany.com")
-          user.confirm!
+          user.confirm
         end
 
         it "is sent from the default email" do

spec/models/user_spec.rb

@@ -188,7 +188,7 @@ describe User do
     end
 
     it 'confirms a user' do
-      user.confirm!
+      user.confirm
       expect(user.confirmed?).to be_truthy
     end
   end