add Dockerfile for CI docker image

testing/Dockerfile

+FROM debian:buster
+ENV DEBIAN_FRONTEND noninteractive
+
+RUN apt-get update && apt-get install -y wget gnupg2 software-properties-common procps rsync xvfb
+
+RUN wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox_2016.asc -O- | apt-key add - \
+	&& wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc -O- | apt-key add - \
+	&& apt-add-repository "deb http://download.virtualbox.org/virtualbox/debian buster contrib" \
+	&& apt-get update \
+	&& apt-get install -y virtualbox-6.1
+
+RUN wget https://releases.hashicorp.com/vagrant/2.2.16/vagrant_2.2.16_x86_64.deb \
+		&& dpkg -i vagrant_2.2.16_x86_64.deb
+
+RUN apt-add-repository "deb http://ppa.launchpad.net/ansible/ansible/ubuntu trusty main" \
+	&& apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 93C4A3FD7BB9C367 \
+	&& apt-get update \
+	&& apt-get install -y ansible
+
+RUN apt-get update \
+	&& apt-get install -y git python3-pip \
+	&& pip3 install setuptools