Remove obsolete Group tag

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

rubygem-cairo.spec

@@ -13,7 +13,6 @@ Summary:	Ruby bindings for cairo
 Name:		rubygem-%{gem_name}
 Version:	%{gemver}
 Release:	2%{?dist}
-Group:		Development/Languages
 License:	GPLv2 or Ruby
 URL:		http://cairographics.org/rcairo/
 %if 1
@@ -66,7 +65,6 @@ X Window System, win32, and image buffers.
 
 %package	doc
 Summary:	Documentation for %{name}
-Group:		Documentation
 Requires:	%{name} = %{version}-%{release}
 
 %description	doc
@@ -74,7 +72,6 @@ This package contains documentation for %{name}.
 
 %package	devel
 Summary:	Ruby-cairo development environment
-Group:		Development/Languages
 Requires:	%{name} = %{version}-%{release}
 Requires:	cairo-devel
 Requires:	ruby-devel