Improve test suite for unnecessary quotes (#8011)
Improve test suite for unnecessary quotes (#8011)

Tests for uppercase atoms/keywords were passing even if the code
was emitting warnings.

elixir-lang/elixir,pedrosnk/elixir,kelvinst/elixir,kelvinst/elixir,ggcampinho/elixir,kimshrier/elixir,lexmag/elixir,kimshrier/elixir,joshprice/elixir,michalmuskala/elixir,ggcampinho/elixir,lexmag/elixir,pedrosnk/elixir