introduce spec file and related build scripts

The repository now contains a Vagrantfile for running the testing script
against an RPM package created locally using `make rpm`. To run this
test use `make vagrant-test`. setup.py was also modified to adhere to
packaging guidelines and not to install system-level executables.
The lincense is now included in the Python package using the MANIFEST.in
file.

osbuild.spec

@@ -0,0 +1,76 @@
+%global         pypi_name osbuild
+
+Name:           %{pypi_name}
+Version:        1
+Release:        1%{?dist}
+License:        ASL 2.0
+
+URL:            https://github.com/larskarlitski/osbuild
+
+Source0:        https://github.com/larskarlitski/%{pypi_name}/archive/%{version}.tar.gz
+BuildArch:      noarch
+Summary:        A build system for OS images
+
+BuildRequires:  python3-devel
+
+Requires: bash
+Requires: coreutils
+Requires: dnf
+Requires: e2fsprogs
+Requires: glibc
+Requires: policycoreutils
+Requires: qemu-img
+Requires: systemd
+Requires: systemd-container
+Requires: tar
+Requires: util-linux
+Requires: python3-%{pypi_name}
+
+%{?python_enable_dependency_generator}
+
+%description
+A build system for OS images
+
+%package -n     python3-%{pypi_name}
+Summary:        %{summary}
+%{?python_provide:%python_provide python3-%{pypi_name}}
+
+%description -n     python3-%{pypi_name}
+A build system for OS images
+
+%prep
+%autosetup -n %{name}-%{version}
+
+%build
+%py3_build
+
+%install
+%py3_install
+
+mkdir -p %{buildroot}%{_libexecdir}/%{pypi_name}/stages
+install -p -m 0755 stages/* %{buildroot}%{_libexecdir}/%{pypi_name}/stages/
+
+mkdir -p %{buildroot}%{_libexecdir}/%{pypi_name}/assemblers
+install -p -m 0755 assemblers/* %{buildroot}%{_libexecdir}/%{pypi_name}/assemblers/
+
+install -p -m 0755 osbuild-run %{buildroot}%{_libexecdir}/%{pypi_name}/
+
+%check
+exit 0
+# We have some integration tests, but those require running a VM, so that would
+# be an overkill for RPM check script.
+
+%files
+%license LICENSE
+%{_bindir}/osbuild
+%{_libexecdir}/%{pypi_name}
+
+%files -n     python3-%{pypi_name}
+%license LICENSE
+%doc README.md
+%{python3_sitelib}/%{pypi_name}-*.egg-info/
+%{python3_sitelib}/%{pypi_name}/
+
+%changelog
+* Wed Jul 17 2019 Martin Sehnoutka <msehnout@redhat.com> - 1-1
+- Initial package