It's a thin layer to provide easy access to sample files throughout
test-cases. This adds the directory `test/fixtures/files` to newly
generated applications.
AS::TC::ConstantLookup walks the test's name to find the constant it is describing.
This additional lookup logic is needed to better support minitest's spec DSL.
To facilitate the use of ActiveSupport::Testing::Performance outside
of a Rails application conditionally check for the presence of
Rails::VERSION::STRING before including it in the environment string.
