Remove arity check that does not work with ActiveRecord objects

The save method a standard ActiveRecord object has an Arity of -1, not 1 as expected by this code.

```
User.first.method(:save).arity
> -1
```

The effect is that when we pass in a validation context it is not used.

lib/wicked/controller/concerns/render_redirect.rb

@@ -16,7 +16,7 @@ def render_wizard(resource = nil, options = {}, params = {})
   def process_resource!(resource, options = {})
     return unless resource
 
-    if options[:context] && resource.method(:save).arity >= 1
+    if options[:context]
       did_save = resource.save(context: options[:context])
     else
       did_save = resource.save