cleanup docker files and build/test procedure

docker/ubuntu-20.04.Dockerfile

@@ -0,0 +1,34 @@
+FROM ubuntu:20.04
+
+ARG DEBIAN_FRONTEND=noninteractive
+ARG mscpdir="/mscp"
+
+COPY . ${mscpdir}
+
+RUN set -ex && apt-get update && apt-get install -y --no-install-recommends \
+	ca-certificates
+
+# install numpy and pytest, and sshd for test
+RUN apt-get install -y --no-install-recommends  \
+        python3 python3-pip openssh-server
+
+RUN python3 -m pip install numpy pytest
+
+
+# preparation for sshd
+RUN  mkdir /var/run/sshd        \
+        && ssh-keygen -f /root/.ssh/id_rsa -N ""                \
+        && mv /root/.ssh/id_rsa.pub /root/.ssh/authorized_keys
+
+
+# install build dependency
+RUN ${mscpdir}/scripts/install-build-deps.sh
+
+
+# build
+RUN cd ${mscpdir}			\
+	&& rm -rf build			\
+	&& cmake -B build -DBUILD_PKG=1	\
+	&& cd ${mscpdir}/build		\
+	&& make				\
+	&& cpack -G DEB CPackConfig.cmake