Add metapackage for dependencies

Currently we are not able to use python dependencies correctly to
ensure the RPM will not be removed during the upgrade of the system.
As a workround, put all such system dependencies into the leapp-deps
metapackage.

This metapackage is supposed to be built for the same system where
leapp should be installed. When different dependencies are needed
on target system (e.g. during the in-place upgrade) repository is
reponsible to deliver new meta package with such dependencies.

Leapp framework from this point will require specific capability:
  leapp-framework-dependencies

which has to be provided by such meta package. Any time the
dependencies are changed, the capability number has to be incremented
by one. So packages provided by leapp repository has to reflect such
change as well.

packaging/leapp.spec

@@ -30,6 +30,7 @@ Requires: python2-%{name} = %{version}-%{release}
 %endif
 Requires: leapp-repository >= %{version}
 
+
 %description
 Leapp tool for handling upgrades.
 
@@ -77,20 +78,47 @@ BuildRequires:  python2-pytest-cov
 BuildRequires:  python2-setuptools
 
 %endif
-%if 0%{?rhel} && 0%{?rhel} == 7
-Requires: /usr/lib/python2.7/site-packages/six.py
-Requires: /usr/lib/python2.7/site-packages/setuptools/__init__.py
-%else
-Requires: python2-six
-Requires: python2-setuptools
-%endif
-Requires: findutils
+
+# IMPORTANT: everytime the requirements are changed, increment number by one
+# - same for Provides in deps subpackage
+Requires: leapp-framework-dependencies = 1
 
 %description -n python2-%{name}
 Python 2 leapp framework libraries.
 
 %endif
 
+# FIXME:
+# this subpackages should be used by python2-%{name} - so it makes sense to
+# improve name and dependencies inside - do same subpackage for python3-%{name}
+%package deps
+Summary:    Meta-package with system dependencies of %{name} package
+
+# IMPORTANT: everytime the requirements are changed, increment number by one
+# same for requiremenrs in main package above
+Provides: leapp-framework-dependencies = 1
+##################################################
+# Real requirements for the leapp HERE
+##################################################
+# NOTE: ignore Python3 completely now
+%if 0%{?rhel} && 0%{?rhel} == 7
+Requires: python-six
+Requires: python-setuptools
+%else
+%if %{with python3}
+Requires: python3-six
+Requires: python3-setuptools
+%else # with python2
+Requires: python2-six
+Requires: python2-setuptools
+%endif
+%endif
+Requires: findutils
+##################################################
+# end requirements here
+##################################################
+%description deps
+%{summary}
 
 ##################################################
 # Python 3 library package
@@ -110,8 +138,7 @@ BuildRequires:  python3-setuptools
 BuildRequires:  python3-pytest-cov
 %endif
 
-Requires: python3-six
-Requires: findutils
+Requires: leapp-framework-dependencies = 1
 
 %description -n python3-%{name}
 Python 3 leapp framework libraries.
@@ -210,6 +237,10 @@ install -m 0644 -p man/snactor.1 %{buildroot}%{_mandir}/man1/
 
 %endif
 
+#FIXME: in case of rename, put those subpkgs under relevant if statement
+%files deps
+# no files here
+
 %changelog
 * Mon Apr 16 2018 Vinzenz Feenstra <[email protected]> - %{version}-%{release}
 - Initial rpm