Use custom pip while waiting for pypa/pip#9077

Author: mayeut

tests/integration/test_manylinux.py

@@ -154,7 +154,7 @@ def tmp_docker_image(base, commands, setup_env={}):
 @pytest.fixture(scope='session')
 def docker_python_img():
     """The Python base image with up-to-date pip"""
-    with tmp_docker_image(PYTHON_IMAGE_ID, ['pip install -U pip']) as img_id:
+    with tmp_docker_image(PYTHON_IMAGE_ID, ['pip install -U git+https://github.com/mayeut/pip.git@8a32226fc82cb9dd97018ac14f45325944ceebdd']) as img_id:
         yield img_id
 
 @pytest.fixture(scope='session', params=MANYLINUX_IMAGES.keys())