Hi,
I managed to get this to work but had to ensure that I used the value of the entityId of the SP for the providerID parameter. To determine the entity if you may have to look at the metadata file for the SP. in my instance I had generated the SP metadata so o just had to open the generated FileVault to determine the appropriate entityId. I didn't even bother with the target value and instead let the trust config determine the target.
See https://wiki.shibboleth.net/confluence/display/IDP30/UnsolicitedSSOConfiguration for config details.
Dan