Ensure python black runs on all .py files (#2827)

diff --git a/Makefile b/Makefile
index fff1df5..53cea3b 100644
--- a/Makefile
+++ b/Makefile
@@ -213,7 +213,7 @@
 	@python3 -c "import sys; exit(1 if sys.version_info >= (3,6) else 0)" || \
 		LC_ALL=C.UTF-8 LANG=C.UTF-8 .venv/bin/black --check \
 		--exclude="build/|buck-out/|dist/|_build/|\.git/|\.hg/|\.mypy_cache/|\.nox/|\.tox/|\.venv/|src/rebar/pr2relnotes.py|src/fauxton" \
-		. dev/run test/javascript/run src/mango src/docs
+		build-aux/*.py dev/run test/javascript/run src/mango/test/*.py src/docs/src/conf.py src/docs/ext/*.py .
 
 python-black-update: .venv/bin/black
 	@python3 -c "import sys; exit(1 if sys.version_info < (3,6) else 0)" || \
@@ -221,7 +221,7 @@
 	@python3 -c "import sys; exit(1 if sys.version_info >= (3,6) else 0)" || \
 		LC_ALL=C.UTF-8 LANG=C.UTF-8 .venv/bin/black \
 		--exclude="build/|buck-out/|dist/|_build/|\.git/|\.hg/|\.mypy_cache/|\.nox/|\.tox/|\.venv/|src/rebar/pr2relnotes.py|src/fauxton" \
-		. dev/run test/javascript/run src/mango src/docs
+		build-aux/*.py dev/run test/javascript/run src/mango/test/*.py src/docs/src/conf.py src/docs/ext/*.py .
 
 .PHONY: elixir
 elixir: export MIX_ENV=integration
diff --git a/Makefile.win b/Makefile.win
index 0fc4d91..6c160e8 100644
--- a/Makefile.win
+++ b/Makefile.win
@@ -190,7 +190,7 @@
 	@python.exe -c "import sys; exit(1 if sys.version_info >= (3,6) else 0)" || \
 		.venv\Scripts\black.exe --check \
 		--exclude="build/|buck-out/|dist/|_build/|\.git/|\.hg/|\.mypy_cache/|\.nox/|\.tox/|\.venv/|src/rebar/pr2relnotes.py|src/fauxton" \
-		. dev\run test\javascript\run src\mango src\docs
+		build-aux\*.py dev\run test\javascript\run src\mango\test\*.py src\docs\src\conf.py src\docs\ext\*.py .
 
 python-black-update: .venv/bin/black
 	@python.exe -c "import sys; exit(1 if sys.version_info < (3,6) else 0)" || \
@@ -198,7 +198,7 @@
 	@python.exe -c "import sys; exit(1 if sys.version_info >= (3,6) else 0)" || \
 		.venv\Scripts\black.exe \
 		--exclude="build/|buck-out/|dist/|_build/|\.git/|\.hg/|\.mypy_cache/|\.nox/|\.tox/|\.venv/|src/rebar/pr2relnotes.py|src/fauxton" \
-		. dev\run test\javascript\run src\mango src\docs
+		build-aux\*.py dev\run test\javascript\run src\mango\test\*.py src\docs\src\conf.py src\docs\ext\*.py .
 
 .PHONY: elixir
 elixir: export MIX_ENV=integration