Add pip install requirements in dockerfile for policyapi

microservices/policyApi/Dockerfile

@@ -1,25 +1,13 @@
 FROM python:3.7.0
 
-RUN pip install pyyaml requests gevent && \
-    # FLASK Micro-framework
-    pip install flask flask_compress && \
-    # Mongo SDK
-    pip install mongoengine && \
-    # Amazon EC2/S3 SDK
-    pip install boto3 && \
-    # dot accessible dictionary
-    pip install munch && \
-    # HCL Parser
-    pip install pyhcl
-
-RUN pip install pytest
-
 WORKDIR /app
 
 COPY . .
 
+RUN pip install -r requirements.txt
+
 RUN chmod +x entrypoint.sh
 
 EXPOSE 3004
 
-ENTRYPOINT ["./entrypoint.sh"]
+ENTRYPOINT ["./entrypoint.sh"]