fix staging Dockerfile, which was installing fairgraph from source, then over-riding this by installing from requirements.txt.lock

Author: apdavison

validation_service_api/deployment/Dockerfile.staging

@@ -17,9 +17,7 @@ LABEL org.opencontainers.image.authors="Andrew Davison <andrew.davison@cnrs.fr>"
 
 WORKDIR /code
 
-ADD https://api.github.com/repos/HumanBrainProject/fairgraph/git/refs/heads/master fairgraph_version.json
-RUN git clone https://github.com/HumanBrainProject/fairgraph.git --branch=master --single-branch
-RUN pip install ./fairgraph
+ADD https://api.github.com/repos/HumanBrainProject/fairgraph/git/refs/heads/stable fairgraph_version.json
 
 COPY requirements.txt.lock /code/requirements.txt
 RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt