Fixes duplicated entries when using nested fields

[Nerian]

#57

[dblock]

Put back the * Your contribution here, please, for the next contributor.

[dblock]

Thanks a lot for fixing this. The build failed on Rubocop, use 1.9.x Ruby syntax. Please try to use --amend when updating.

[Nerian]

Done :)

[dblock]

Waait... a second :) The check for _nested is an attribute name check, or am I missing something? If I rename every _nested to _x in the test everything breaks.

[Nerian]

Oh true. For some reason I thought that internally we were using __nested to refer to nested fields. Now I see it's just a coincidence.

[Nerian]

https://github.com/intridea/grape-entity/blob/master/lib/grape_entity/entity.rb#L141

As I understand it, we can say that if there is a '' in the name, it is a nested attribute. I changed the code to check for '' instead of '_nested'

[dblock]

I don't think this is correct or reliable. Why can't I have an attribute with these characters that's not nested? We should be able to add something to options or check against @nested_exposures. I can help you find a better way to figure out whether the attribute is nested if you can't figure it out. I also think you should write a spec for this with more than one level of nesting.

[Nerian]

I agree. So I nuked the branch and started fresh with a test:

Nerian@386f50a#diff-2f09e9dc67c5575f0172b3d0defe0e1bR110

I am not sure how to implement it though.

[dblock]

Closing this in favor of #60. @Nerian please take a look, LMK if that fixed all your known issues.