hotfix for requirements.txt in python runtime

Author: sebgoa

python-3.7/buildtemplate.yaml

@@ -43,6 +43,7 @@ spec:
         ENV _HANDLER "${HANDLER}"
 
         COPY . .
+        RUN if [ -f requirements.txt ]; then pip3.7 install -r requirements.txt ;fi
 
         ENTRYPOINT ["/opt/aws-custom-runtime"]
       EOF