Declare features in openstack_pip provider

Puppet providers can express what features they can provide using the
has_features variable. The declaration of features isn't inherited, so
we need to declare the features that we inherited from the core pip
provider.

Change-Id: I2f4c6254bb7f45649658d6a6b296ea1270ce6364

lib/puppet/provider/package/openstack_pip.rb

@@ -7,6 +7,8 @@ Puppet::Type.type(:package).provide(:openstack_pip, :parent => :pip) do
 
   desc "Python packages via `pip` with mirrors."
 
+  has_feature :installable, :uninstallable, :upgradeable, :versionable
+
   commands :pip => 'pip'
 
   def self.outdated