Remove obsolete Group tag

References: https://fedoraproject.org/wiki/Changes/Remove_Group_Tag

rubygem-minitest-stub-const.spec

@@ -5,7 +5,6 @@ Name: rubygem-%{gem_name}
 Version: 0.5
 Release: 6%{?dist}
 Summary: Stub constants for the duration of a block in MiniTest
-Group: Development/Languages
 License: MIT
 URL: https://github.com/adammck/minitest-stub-const
 Source0: https://rubygems.org/gems/%{gem_name}-%{version}.gem
@@ -22,7 +21,6 @@ Like RSpec's stub_const, but boring and non-magical.
 
 %package doc
 Summary: Documentation for %{name}
-Group: Documentation
 Requires: %{name} = %{version}-%{release}
 BuildArch: noarch