v2.0: Settings params deprecations

[johnnyshields]

Deprecate RubySaml#Settings params and alias them to the new ones. All these deprecations were declared in CHANGELOG in earlier versions already. This does not affect any existing behavior.

• issuer --> sp_entity_id
• idp_sso_target_url --> idp_sso_service_url
• idp_slo_target_url --> idp_slo_service_url
• assertion_consumer_logout_service_url --> single_logout_service_url
• assertion_consumer_logout_service_binding --> single_logout_service_binding

[johnnyshields]

@pitbulk ready for review and merge.

[pitbulk]

Merging this one, but we need to be careful when we move to 2.1

Maintaining clean code is nice, but it's not cool if you break several projects while doing this.

Suppose you execute a simple search on Github. In that case, you will find that tons of projects still use settings.issuer, so imagine all those projects using ruby-saml in real production environments that added SAML support years ago (when this parameter was in use). I'm pretty sure that is possible that the developer that made the integration could not be anymore in the company. Nobody going to be aware of the change that is required or will not notice the need for the change until the integration breaks.

[johnnyshields]

we need to be careful when we move to 2.1

In version 2.1.0 I am thinking we should keep the methods but raise a hard RuntimeError Settings#issuer parameter has been removed in RubySaml v2.1.0 and migrated to Settings#sp_entity_id. Please downgrade to RubySaml v2.0.0 and fix all deprecation warnings before upgrading to v2.1.0.

It is very likely users will see this error at application boot time, or in their tests. If they don't see it, they are doing something massively wrong.