Build docker file

# add "RUN apt-get upgrade -y" to docker file
vim flexbuild_lsdk2012/docker/ubuntu/Dockerfile
add "RUN apt-get upgrade -y" to docker file

# Build docker file
docker build -t wlsdk:18.04 . --no-cache


adv@adv-desktop3:~/William/LSDK2012_0825_dockerfile_qspi/flexbuild_lsdk2012/docker/ubuntu$ docker images
REPOSITORY                    TAG                 IMAGE ID            CREATED             SIZE
wlsdk                         18.04               b988eaa3bb66        22 seconds ago      1.28GB
fbubuntu                      18.04               a1d6e6413e69        29 hours ago        1.28GB