added tests for Attribute class

modules/t/attribute.t

+use lib 't';
+
+use strict;
+use warnings;
+
+use Bio::EnsEMBL::Attribute;
+
+use TestUtils qw(debug test_getter_setter);
+
+our $verbose = 0; #set to 1 to turn on debug printouts
+
+BEGIN { $| = 1;
+	use Test;
+	plan tests => 8;
+}
+
+use TestUtils qw( debug test_getter_setter );
+
+#
+# test constructor
+#
+
+my $code = 'testcode';
+my $name = 'testname';
+my $desc = 'testdesc';
+my $value = 'testval';
+
+my $attrib = Bio::EnsEMBL::Attribute->new
+  (-CODE => $code,
+   -NAME => $name,
+   -DESC => $desc,
+   -VALUE => $value);
+
+ok($attrib->code()  eq $code);
+ok($attrib->name()  eq $name);
+ok($attrib->desc()  eq $desc);
+ok($attrib->value() eq $value);
+
+#
+# test getter/setters
+#
+ok(test_getter_setter($attrib, 'name', 'newname'));
+ok(test_getter_setter($attrib, 'code', 'newcode'));
+ok(test_getter_setter($attrib, 'desc', 'newdesc'));
+ok(test_getter_setter($attrib, 'value', 'newvalue'));
+