Rails RC1 and Minor Ruby Bumps for Testing

This is where JRuby becomes 2.3 compatible.

Update rails version in description

Update repo name in README

Add scope without_deleted

Callbacks are countable, use several instead of few to reference them

Add a without_deleted scope to manually exclude paranoia-deleted records, which is essentially the paranoia_scope.
Useful when using the option :without_default_scope or the unscoping of a paranoia-model was required.
Aliased it to the paranoia_scope as opposed to the existing with_deleted scope.

Rails 5 Support, Require ruby 2.0

Just for consitency. alias_method is easier to reason about than
only_deleted.

Also updates ruby versions

In rails 4.x this passed around a set of arel conditions, in rails 5 it
passes around an AR::Relation and uses where().

See rails/rails@5f521cbff3c8a46cfc8e16b234294a20c285d00d

It is unnecessary to test the AR internals here. Testing the
where_values_hash should be sufficient.

We are switching to support of ruby 2.0 and greater. We will only
support jruby OVER 9000 for feature parity.

alias defines these on ActiveRecord::Base itself, which is not what was
intended. This behaviour previous differed between MRI and jruby.

Added without_default_scope option

Fix typo in readme

Update location of acts_as_paranoid repository

Fix grammar and typos in README