Restrict a few failing tests to run on the right Ruby versions.

spec/fakefs/fakefs_bug_ruby_2.1.0-preview2_spec.rb

@@ -6,10 +6,12 @@
   c.include(FakeFS::SpecHelpers, :fakefs => true)
 end
 
-describe 'Find.find', :fakefs => true do
-  it 'does not give an ArgumentError' do
-    FileUtils.mkdir_p('/tmp/foo')
-    found = Find.find('/tmp').to_a
-    expect(found).to eq(%w(/tmp /tmp/foo))
+if RUBY_VERSION >= '2.1'
+  describe 'Find.find', :fakefs => true do
+    it 'does not give an ArgumentError' do
+      FileUtils.mkdir_p('/tmp/foo')
+      found = Find.find('/tmp').to_a
+      expect(found).to eq(%w(/tmp /tmp/foo))
+    end
   end
 end

test/fakefs_test.rb

@@ -572,20 +572,22 @@ def test_raises_error_on_mtime_if_file_does_not_exist
     end
   end
 
-  def test_can_set_mtime_on_new_file_touch_with_param
-    time = Time.new(2002, 10, 31, 2, 2, 2, "+02:00")
-    FileUtils.touch("foo.txt", :mtime => time)
+  if RUBY_VERSION >= "1.9"
+    def test_can_set_mtime_on_new_file_touch_with_param
+      time = Time.new(2002, 10, 31, 2, 2, 2, "+02:00")
+      FileUtils.touch("foo.txt", :mtime => time)
 
-    assert_equal File.mtime("foo.txt"), time
-  end
+      assert_equal File.mtime("foo.txt"), time
+    end
 
-  def test_can_set_mtime_on_existing_file_touch_with_param
-    FileUtils.touch("foo.txt")
+    def test_can_set_mtime_on_existing_file_touch_with_param
+      FileUtils.touch("foo.txt")
 
-    time = Time.new(2002, 10, 31, 2, 2, 2, "+02:00")
-    FileUtils.touch("foo.txt", :mtime => time)
+      time = Time.new(2002, 10, 31, 2, 2, 2, "+02:00")
+      FileUtils.touch("foo.txt", :mtime => time)
 
-    assert_equal File.mtime("foo.txt"), time
+      assert_equal File.mtime("foo.txt"), time
+    end
   end
 
   def test_can_return_mtime_on_existing_file