add Dockerfile-test for test container

docker/Dockerfile-test

@@ -0,0 +1,30 @@
+FROM ubuntu:latest
+
+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
+
+
+# build 
+RUN ${mscpdir}/install-build-deps.sh
+
+RUN cd ${mscpdir}			\
+	&& rm -rf build			\
+	&& mkdir build && cd build	\
+	&& cmake .. && make	

docker/README.md

@@ -17,4 +17,15 @@ docker run -it --rm -v (pwd):/out mscp-centos:8 \
        cp /mscp/build/mscp_0.0.0-centos-8-x86_64.rpm /out/
 ```
 
-I don't know whether this is a good way.
+
+Test `mscp` in a ubuntu:latest docker container.
+
+```console
+cd ..
+
+docker build --rm -t mscp-test -f docker/Dockerfile-test .
+
+docker run --init -it --rm mscp-test bash -c "/usr/sbin/sshd; cd /mscp/build; ctest --verbose"
+```
+
+I don't know whether these these are good way.