Adds ln stestr-3 and stestr-%{python3_version} back

The command 'stestr-3' is missed after upgrade in
https://gitee.com/src-openeuler/python-stestr/pulls/12
This adds the lns back.

(cherry picked from commit 52aa2cb0c36614975f0857166692be2fd490f01c)

stestr.spec

@@ -1,7 +1,7 @@
 %global _empty_manifest_terminate_build 0
 Name:           python-stestr
 Version:        3.1.0
-Release:        1
+Release:        2
 Summary:        A parallel Python test runner built around subunit
 License:        Apache-2.0
 URL:            http://stestr.readthedocs.io/en/latest/
@@ -56,6 +56,8 @@ A parallel Python test runner built around subunit
 
 %install
 %py3_install
+ln -s stestr %{buildroot}/%{_bindir}/stestr-3
+ln -s stestr-3 %{buildroot}/%{_bindir}/stestr-%{python3_version}
 
 install -d -m755 %{buildroot}/%{_pkgdocdir}
 if [ -d doc ]; then cp -arf doc %{buildroot}/%{_pkgdocdir}; fi
@@ -88,11 +90,15 @@ mv %{buildroot}/doclist.lst .
 
 %files -n python3-stestr -f filelist.lst
 %dir %{python3_sitelib}/*
+%{_bindir}/stestr*
 
 %files help -f doclist.lst
 %{_docdir}/*
 
 %changelog
+* Thu Aug 12 2021 huangtianhua <huangtianhua@huawei.com> - 3.1.0-2
+- Adds ln stestr-3 and stestr-%{python3_version}
+
 * Tue Aug 10 2021 OpenStack_SIG <openstack@openeuler.org> - 3.1.0-1
 - update to 3.1.0