Update README to use proper version for Rails 5

Update homepage in gemspec

The homepage is supposed to be where you can find the code. It is displayed on rubygems.org page. Currently it will redirect you back to the same page. Should point at this github repo.

update the gemspec fields to reduce warnings

Rails 5

Update travis for rails 5

Fixed README for rails 5.

Typo

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.