Merge ActionController::Parameters with rails 5
<p>In rails 4, I can merge! StrongParams, but since rails 5 (beta1) merge! is not available. Which is the best way to do that in a controller</p>

<pre><code>  params = ActionController::Parameters.new({
             name: 'Francesco',
             age:  22,
             role: 'admin'
         })
         params.merge!(city: "Los Angeles")
</code></pre>