Bump simple_form from 3.1.0.rc2 to 4.0.0

Bumps [simple_form](https://github.com/plataformatec/simple_form) from 3.1.0.rc2 to 4.0.0.
- [Release notes](https://github.com/plataformatec/simple_form/releases)
- [Changelog](https://github.com/plataformatec/simple_form/blob/master/CHANGELOG.md)
- [Commits](https://github.com/plataformatec/simple_form/compare/v3.1.0.rc2...v4.0.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Gemfile

@@ -31,7 +31,7 @@ gem 'meta-tags', require: 'meta_tags'
 gem 'haml-rails'
 gem 'ruby-haml-js'
 gem 'slim'
-gem 'simple_form', '3.1.0.rc2'
+gem 'simple_form', '4.0.0'
 gem 'friendly_id'
 
 gem 'rack-throttle', '~> 0.3.0'

Gemfile.lock

@@ -513,9 +513,9 @@ GEM
       rufus-scheduler (~> 3.2)
       sidekiq (>= 3)
       tilt (>= 1.4.0)
-    simple_form (3.1.0.rc2)
-      actionpack (~> 4.0)
-      activemodel (~> 4.0)
+    simple_form (4.0.0)
+      actionpack (> 4)
+      activemodel (> 4)
     sinatra (1.4.8)
       rack (~> 1.5)
       rack-protection (~> 1.4)
@@ -642,7 +642,7 @@ DEPENDENCIES
   sidekiq
   sidekiq-failures
   sidekiq-scheduler (~> 2.0)
-  simple_form (= 3.1.0.rc2)
+  simple_form (= 4.0.0)
   sinatra
   slim
   soundmanager-rails