devel/py-dpcontracts: Convert to USE_PYTHON=pep517

- Bump PORTREVISION for package change

devel/py-dpcontracts/Makefile

 PORTNAME=	dpcontracts
 PORTVERSION=	0.6.0
+PORTREVISION=	1
 CATEGORIES=	devel python
 MASTER_SITES=	PYPI
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
@@ -10,8 +11,11 @@ WWW=		https://github.com/deadpixi/contracts
 
 LICENSE=	LGPL3+
 
+BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}setuptools>=0:devel/py-setuptools@${PY_FLAVOR} \
+		${PYTHON_PKGNAMEPREFIX}wheel>=0:devel/py-wheel@${PY_FLAVOR}
+
 USES=		python
-USE_PYTHON=	autoplist concurrent distutils
+USE_PYTHON=	autoplist concurrent pep517
 
 NO_ARCH=	yes