dev-python/more-itertools: tests: don't load docs/conf.py

docs/conf.py imports sphinx_rtd_theme which isn't guaranteed to be
installed.

Bug: https://bugs.gentoo.org/659002
Package-Manager: Portage-2.3.40, Repoman-2.3.9

dev-python/more-itertools/more-itertools-4.2.0.ebuild

@@ -36,5 +36,6 @@ python_compile_all() {
 }
 
 python_test() {
-	py.test --doctest-modules || die "tests fail with ${EPYTHON}"
+	py.test --doctest-modules more_itertools \
+		|| die "tests fail with ${EPYTHON}"
 }