Remove old Tempfile tests from Thumbnail spec

spec/paperclip/thumbnail_spec.rb

 require 'spec_helper'
 
 describe Paperclip::Thumbnail do
-  context "A Paperclip Tempfile" do
-    before do
-      @tempfile = Paperclip::Tempfile.new(["file", ".jpg"])
-    end
-
-    after { @tempfile.close }
-
-    it "has its path contain a real extension" do
-      assert_equal ".jpg", File.extname(@tempfile.path)
-    end
-
-    it "is a real Tempfile" do
-      assert @tempfile.is_a?(::Tempfile)
-    end
-  end
-
-  context "Another Paperclip Tempfile" do
-    before do
-      @tempfile = Paperclip::Tempfile.new("file")
-    end
-
-    after { @tempfile.close }
-
-    it "does not have an extension if not given one" do
-      assert_equal "", File.extname(@tempfile.path)
-    end
-
-    it "is a real Tempfile" do
-      assert @tempfile.is_a?(::Tempfile)
-    end
-  end
-
   context "An image" do
     before do
       @file = File.new(fixture_file("5k.png"), 'rb')