Update dependency voxpupuli-acceptance to v4

Author: renovate[bot]

Gemfile

@@ -21,7 +21,7 @@ group :development do
 end
 
 group :system_tests do
-  gem 'voxpupuli-acceptance', '~> 3.5',  :require => false
+  gem 'voxpupuli-acceptance', '~> 4.0',  :require => false
 end
 
 group :release do