Update poise-python to latest stable

poise received a round of updates, so let's remove the funky workaround.

Change-Id: I657bfd5459f6973a4ae420bf9b5c87039ab1529d

metadata.rb

@@ -18,7 +18,7 @@ depends 'etcd', '~> 3.0'
 depends 'mariadb', '~> 1.5'
 depends 'memcached', '~> 4.1'
 depends 'mysql', '~> 8.2'
-depends 'poise-python', '~> 1.5'
+depends 'poise-python', '~> 1.7'
 depends 'selinux'
 
 issues_url 'https://launchpad.net/openstack-chef' if respond_to?(:issues_url)

recipes/default.rb

@@ -18,16 +18,9 @@
 # limitations under the License.
 #
 
-# install a python, working around the epoch on RHEL
-case node['platform_family']
-when 'debian', 'ubuntu'
-  python_runtime '2' do
-    provider :system
-  end
-when 'rhel'
-  python_runtime '0:2' do
-    provider :system
-  end
+# install a python
+python_runtime '2' do
+  provider :system
 end
 
 platform_options = node['openstack']['common']['platform']