sci-chemistry/chemex: Support python 3.9, fix tests

Closes: https://bugs.gentoo.org/738242
Thanks-to: Agostino Sarubbo
Package-Manager: Portage-3.0.14, Repoman-3.0.2
Signed-off-by: Pacho Ramos <pacho@gentoo.org>

sci-chemistry/chemex/chemex-2018.10.3.ebuild

@@ -1,10 +1,10 @@
-# Copyright 1999-2020 Gentoo Authors
+# Copyright 1999-2021 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=7
 DISTUTILS_SINGLE_IMPL="yes"
 DISTUTILS_USE_SETUPTOOLS=rdepend
-PYTHON_COMPAT=( python3_{7..8} )
+PYTHON_COMPAT=( python3_{7..9} )
 
 inherit distutils-r1
 
@@ -30,13 +30,11 @@ RDEPEND="
 "
 DEPEND="${RDEPEND}"
 
+distutils_enable_tests pytest
+
 S="${WORKDIR}/ChemEx-${PV}"
 
 src_prepare() {
 	export SETUPTOOLS_SCM_PRETEND_VERSION="${PV}"
 	distutils-r1_src_prepare
 }
-
-python_test() {
-	py.test -v -v || die
-}