fix generators template bug

[regonn]

My environment is

rails 4.2.3
active_model_serializers 0.10.0.rc2

When I executed this code

$ bin/rails g resource item name:string price:integer user:references

and generate this code

class ItemSerializer < ActiveModel::Serializer
  attributes :id, :name, :price
end
  attribute :user 

I think generator template has a bug, and I fixed it.

[joaomdmoura]

@regonn hmm, this is strange. Indeed it seems that the test we have right now don't test the whole file, but only use assert_match.
Could you write a test to this? 😄

[bf4]

@joaomdmoura Partly my bad for not adding one in my previous two revisions of the generator :(

[regonn]

@joaomdmoura I added assert_match test.
I couldn't find an example of file tail test at other gem repository. Do you have another idea?

[joaomdmoura]

no worries @bf4 😄 you all have being doing an awesome work here!
@regonn I think this is the most straightforward way to test it too 😄
I'm cool with it, just ran the test against master it was indeed breaking.
I'm merging it.