include pip constraints in Dockerfile

deploy/docker/Dockerfile

@@ -8,6 +8,8 @@ WORKDIR /code
 
 # Layer 1: Install dependencies
 COPY requirements.txt /code
+COPY constraints.txt /code
+ENV PIP_CONSTRAINT=/code/constraints.txt
 RUN pip3 install --no-cache-dir -r requirements.txt
 
 # Layer 2: Install nucypher entrypoint