Remove obsolete Group tag

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

rubygem-thor.spec

@@ -8,7 +8,6 @@ Summary: Thor is a toolkit for building powerful command-line interfaces
 Name: rubygem-%{gem_name}
 Version: 0.19.1
 Release: 9%{?dist}
-Group: Development/Languages
 License: MIT
 URL: http://whatisthor.com/
 Source0: http://rubygems.org/downloads/%{gem_name}-%{version}.gem
@@ -33,7 +32,6 @@ Thor is a toolkit for building powerful command-line interfaces.
 
 %package doc
 Summary: Documentation for %{name}
-Group: Documentation
 Requires: %{name} = %{version}-%{release}
 BuildArch: noarch