Use text_area instead of cktext_area

We're going to change CKEditor to an inline editor, and the "ckeditor"
gem doesn't provide an option to do so.

Since using `cktext_area` would automatically generate a "classic"
iframe CKEditor, we need to use `text_area` and load the editor using
JavaScript. Personally I prefer this option anyway.

Note in the jQuery selector we need to use `textarea.html-area`; using
just `.html-area` would fail if there's an error message associated to
the textarea, since Rails will add the `.html-area` class to the error
message.

lib/consul_form_builder.rb

@@ -9,7 +9,7 @@ class ConsulFormBuilder < FoundationRailsHelper::FormBuilder
     select attribute, choices, options, html_options
   end
 
-  %i[text_field text_area cktext_area number_field password_field email_field].each do |field|
+  %i[text_field text_area number_field password_field email_field].each do |field|
     define_method field do |attribute, options = {}|
       label_with_hint(attribute, options.merge(label_options: label_options_for(options))) +
         super(attribute, options.merge(