Create radio buttons in the presence of extra attributes

In the current code base, if you add an extra attribute to a radio button with code like:

```ruby
<%= f.radio_button :do_thing, true, text: "Yes", required: true %>
```

foundation rails helper will generate a radio button and a label; it will then, however, throw the radio button away.

The regular expression intended to insert the radio button inside the label tag assumes that the `for` attribute on the label is the last one, and is followed immediately by the closing `>`. In the presence of extra attributes, the extra attributes come last and break this assumption.

My fix replaces the broken regex with a non-greedy search of the entire label tag, which makes it insensitive to extra attributes.