Cleanup old Linter tests for valid pages/posts

Author: stomar

test/fixtures/ok/_data/releases.yml

@@ -10,20 +10,11 @@
 describe Linter do
 
   before do
-    @md_ok = "#{FIXTURES_PATH}/ok"
     @md_errors = "#{FIXTURES_PATH}/errors"
 
-    @output_ok = File.read("#{FIXTURES_PATH}/output_ok.txt")
     @output_errors = File.read("#{FIXTURES_PATH}/output_errors.txt")
   end
 
-  it "can run ok" do
-    Dir.chdir @md_ok
-    stdout, _stderr = capture_io { Linter.new(exit_on_errors: false).run }
-
-    _(stdout).must_equal @output_ok
-  end
-
   it "can find errors" do
     Dir.chdir @md_errors
     stdout, _stderr = capture_io { Linter.new(exit_on_errors: false).run }