Add dockerfile for the ci

Dockerfile

+FROM python:2.7.14-stretch
+
+RUN mkdir /kubespray
+WORKDIR /kubespray
+RUN apt update -y && \
+    apt install -y \
+    libssl-dev python-dev sshpass apt-transport-https \
+    ca-certificates curl gnupg2 software-properties-common
+RUN curl -fsSL https://download.docker.com/linux/$(. /etc/os-release; echo "$ID")/gpg | apt-key add - && \
+    add-apt-repository \
+    "deb [arch=amd64] https://download.docker.com/linux/$(. /etc/os-release; echo "$ID") \
+    $(lsb_release -cs) \
+    stable" \
+    && apt update -y && apt-get install docker-ce -y
+
+COPY . .
+RUN pip install -r tests/requirements.txt && pip install -r requirements.txt