Do not use a collection as the default object. Fixes #142

[mrbrdo]

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[nesquena]

Thanks for contributing. I can see how this could fix the issue you mentioned earlier if a collection happens to match the controller name

[mrbrdo]

@nesquena You might want to also consider coercing to array using to_a in data_name
https://github.com/nesquena/rabl/blob/master/lib/rabl/helpers.rb#L31

Current code there might be causing a similar problem in some cases, since it's calling #first, better would be to_a.first. I didn't want to change that because I can see a potential issue if you do something like

collection @stuff.limit(5)

It is necessary to consider stuff like this if calling to_a, so that it won't load all the models if the user isn't using them in the template. Might be a non-issue though, depending on where data_name is called (I did not look too much into it). Would be nice if you could look into that too.