Update Dockerfile

Author: lyou

docker/cpu/Dockerfile

@@ -46,6 +46,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 
 RUN pwd && \
       git clone https://github.com/microsoft/vcpkg.git  && \
+      ls -l && \
       ./vcpkg/bootstrap-vcpkg.sh && \
       vcpkg integrate install && \
       vcpkg install protobuf[zlib] --triplet x64-linux