Remove obsolete Group tag

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

rubygem-timecop.spec

@@ -4,7 +4,6 @@ Summary: Provides a unified method to mock Time.now, Date.today in a single call
 Name: rubygem-%{gem_name}
 Version: 0.7.1
 Release: 7%{?dist}
-Group: Development/Languages
 License: MIT
 URL: https://github.com/travisjeffery/timecop
 Source0: http://rubygems.org/downloads/%{gem_name}-%{version}.gem
@@ -24,7 +23,6 @@ Time.now, Date.today, and DateTime.now in a single call.
 
 %package doc
 Summary: Documentation for %{name}
-Group: Documentation
 Requires:%{name} = %{version}-%{release}
 
 %description doc