[WIP] slim docker base image for lmnet

[tsawada]

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
4 out of 10 committers have signed the CLA.

:white_check_mark: iizukak
:white_check_mark: odoku
:white_check_mark: kchygoe
:white_check_mark: primenumber
:x: ruimashita
:x: Joeper214
:x: lm-jira
:x: nlpng
:x: tsawada
:x: lm-konda
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 10 committers have signed the CLA.

:white_check_mark: iizukak
:x: odoku
:x: lm-jira
:x: ruimashita
:x: lm-konda
:x: tsawada
:x: primenumber
:x: Joeper214
:x: kchygoe
:x: nlpng
_{You have signed the CLA already but the status is still pending? Let us recheck it.}