spec: pin rspec-puppet to 1.0.1

spec: pin rspec-puppet to 1.0.1

rspec-puppet (2.0.0) was released yesterday[1], this new version broke
puppet-openstack unit tests (undefined method `resource')[2] as talked on
and in a second time to update your specs to 2.0.0 and rspec 3.x`)

[1] https://github.com/rodjek/rspec-puppet/commit/8459e14807977244c00bdbcf190062c529b63474
[2] http://logs.openstack.org/45/105245/6/check/gate-puppet-nova-puppet-unit-3.3/3682541/console.html

Change-Id: Ia41394433be65435fc7de6327a5659b26e1a85a5
Partial-bug: #1417604