Fix manylinux deploy in circleci

Author: arcondello

.circleci/config.yml

@@ -172,7 +172,7 @@ jobs:
           command: |
             for PYBIN in /opt/python/*/bin; do
               if "${PYBIN}/python" -c "import sys; sys.exit(sys.version_info>=(3, 5))"; then continue; fi;
-              "${PYBIN}/pip" install -r requirements.txt
+              "${PYBIN}/pip" install -r python/requirements.txt
               "${PYBIN}/pip" wheel . -w ./wheelhouse
               "${PYBIN}/python" setup.py sdist -d ./dist
             done