Don't set group tags

They are unused in Fedora.

clutter.spec

@@ -17,7 +17,6 @@ Version:       1.26.2
 Release:       1%{?dist}
 Summary:       Open Source software library for creating rich graphical user interfaces
 
-Group:         Development/Libraries
 License:       LGPLv2+
 URL:           http://www.clutter-project.org/
 Source0:       https://download.gnome.org/sources/%{name}/1.26/%{name}-%{version}.tar.xz
@@ -62,7 +61,6 @@ We hope however it can be used for a lot more.
 
 %package devel
 Summary:       Clutter development environment
-Group:         Development/Libraries
 Requires:      %{name}%{?_isa} = %{version}-%{release}
 
 %description devel
@@ -71,7 +69,6 @@ clutter
 
 %package       doc
 Summary:       Documentation for %{name}
-Group:         Documentation
 Requires:      %{name} = %{version}-%{release}
 
 %description   doc
@@ -85,7 +82,6 @@ This package contains documentation for clutter.
 %if 0%{?with_tests}
 %package       tests
 Summary:       Tests for the clutter package
-Group:         Development/Libraries
 Requires:      %{name}%{?_isa} = %{version}-%{release}
 
 %description   tests