PE-1620: test to verify class names handling in retry_action
PE-1620: test to verify class names handling in retry_action

This patch adds a test to verify the
+Puppet::CloudPack::Utils.retry_action+ method can handle
retry_exception hash parameter containing exceptions specified
as strings (or symbols) correctly under all circumstances.
While at it the patch also modernizes the utils spec file
syntax.

puppetlabs/puppetlabs-cloud_provisioner,16nsk/puppetlabs-cloud_provisioner,puppetlabs/puppetlabs-cloud_provisioner