Remove obsolete Group tag

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

rubygem-chronic.spec

@@ -6,7 +6,6 @@ Summary: A natural language date parser
 Name: rubygem-%{gem_name}
 Version: 0.10.2
 Release: 7%{?dist}
-Group: Development/Languages
 License: MIT
 URL: http://github.com/mojombo/chronic
 Source0: http://rubygems.org/gems/%{gem_name}-%{version}.gem
@@ -22,7 +21,6 @@ Chronic is a natural language date/time parser written in pure Ruby.
 
 %package doc
 Summary: Documentation for %{name}
-Group: Documentation
 Requires:%{name} = %{version}-%{release}
 
 %description doc