Prepare for upgrade to rspec 3.0.0.rc1
Prepare for upgrade to rspec 3.0.0.rc1

* remove rspec-instafail, it is not compatible
* convert some uses of `should`'s to `expect`

Signed-off-by: John Foley <430ead2b62c58b9d3efe9818f412657a47cda400@pivotallabs.com>

cloudfoundry-incubator/bosh-openstack-cpi-release,voelzmo/bosh-openstack-cpi-release,loewenstein/bosh-openstack-cpi-release,voelzmo/bosh-openstack-cpi-release,voelzmo/bosh-openstack-cpi-release,cloudfoundry-incubator/bosh-openstack-cpi-release,loewenstein/bosh-openstack-cpi-release,cloudfoundry-incubator/bosh-openstack-cpi-release,loewenstein/bosh-openstack-cpi-release