move tests into proper place

diff --git a/tests/marcelod/imagealphablending_error1.phpt b/ext/gd/tests/imagealphablending_error1.phpt
similarity index 100%
rename from tests/marcelod/imagealphablending_error1.phpt
rename to ext/gd/tests/imagealphablending_error1.phpt

diff --git a/tests/marcelod/imagecolorresolvealpha_error3.phpt b/ext/gd/tests/imagecolorresolvealpha_error3.phpt
similarity index 100%
rename from tests/marcelod/imagecolorresolvealpha_error3.phpt
rename to ext/gd/tests/imagecolorresolvealpha_error3.phpt

diff --git a/tests/marcelod/imagesavealpha_error2.phpt b/ext/gd/tests/imagesavealpha_error2.phpt
similarity index 100%
rename from tests/marcelod/imagesavealpha_error2.phpt
rename to ext/gd/tests/imagesavealpha_error2.phpt