Fixed issue with my own tests and the matchers.

test/matchers/have_attached_file_matcher_test.rb

@@ -5,7 +5,7 @@ class HaveAttachedFileMatcherTest < Test::Unit::TestCase
     setup do
       @dummy_class = reset_class "Dummy"
       reset_table "dummies"
-      @matcher     = have_attached_file(:avatar)
+      @matcher     = self.class.have_attached_file(:avatar)
     end
 
     should "reject a class with no attachment" do

test/matchers/validate_attachment_content_type_matcher_test.rb

@@ -8,7 +8,7 @@ class ValidateAttachmentContentTypeMatcherTest < Test::Unit::TestCase
       end
       @dummy_class = reset_class "Dummy"
       @dummy_class.has_attached_file :avatar
-      @matcher     = validate_attachment_content_type(:avatar).
+      @matcher     = self.class.validate_attachment_content_type(:avatar).
                        allowing(%w(image/png image/jpeg)).
                        rejecting(%w(audio/mp3 application/octet-stream))
     end

test/matchers/validate_attachment_presence_matcher_test.rb

@@ -6,7 +6,7 @@ class ValidateAttachmentPresenceMatcherTest < Test::Unit::TestCase
       reset_table("dummies"){|d| d.string :avatar_file_name }
       @dummy_class = reset_class "Dummy"
       @dummy_class.has_attached_file :avatar
-      @matcher     = validate_attachment_presence(:avatar)
+      @matcher     = self.class.validate_attachment_presence(:avatar)
     end
 
     should "reject a class with no validation" do

test/matchers/validate_attachment_size_matcher_test.rb

@@ -11,7 +11,7 @@ class ValidateAttachmentSizeMatcherTest < Test::Unit::TestCase
     end
 
     context "of limited size" do
-      setup{ @matcher = validate_attachment_size(:avatar).in(256..1024) }
+      setup{ @matcher = self.class.validate_attachment_size(:avatar).in(256..1024) }
 
       should "reject a class with no validation" do
         assert_rejects @matcher, @dummy_class
@@ -34,7 +34,7 @@ class ValidateAttachmentSizeMatcherTest < Test::Unit::TestCase
     end
 
     context "validates_attachment_size with infinite range" do
-      setup{ @matcher = validate_attachment_size(:avatar) }
+      setup{ @matcher = self.class.validate_attachment_size(:avatar) }
 
       should "accept a class with an upper limit" do
         @dummy_class.validates_attachment_size :avatar, :less_than => 1