Merge branch '20.12' of https://github.com/lablup/backend.ai-kernels into 20.12

Author: hephaex

vendor/ngc-pytorch/Dockerfile.20.11-py3

@@ -246,7 +246,7 @@ LABEL ai.backend.kernelspec="1" \
       ai.backend.base-distro="ubuntu16.04" \
       ai.backend.runtime-type="python" \
       ai.backend.runtime-path="/opt/conda/bin/python3" \
-      ai.backend.service-ports="ipython:pty:3000,jupyter:http:8091,jupyterlab:http:8090,vscode:http:8180,tensorboard:http:6006,mlflow-ui:http:5000,nniboard:http:8080"
+      ai.backend.service-ports="ipython:pty:3000,jupyter:http:8091,jupyterlab:http:8090,vscode:http:8180,tensorboard:http:6006,mlflow-ui:preopen:5000,nniboard:preopen:8080"
 
 
 WORKDIR /home/work