Added rsync to testing docker image

.gitlab-ci.yml

@@ -1,5 +1,5 @@
 ---
-image: s3lph/matemat-ci:20181107-01
+image: s3lph/matemat-ci:20181107-02
 
 stages:
 - test

testing/Dockerfile

@@ -8,7 +8,7 @@ RUN sed -re 's/stretch/buster/g' -i /etc/apt/sources.list \
   && chown matemat:matemat -R /var/matemat/db \
   && chown matemat:matemat -R /var/matemat/upload \
   && apt-get update -qy \
-  && apt-get install -y --no-install-recommends file sudo openssh-client git docker.io build-essential lintian \
+  && apt-get install -y --no-install-recommends file sudo openssh-client git docker.io build-essential lintian rsync \
   && python3.6 -m pip install coverage wheel pycodestyle mypy \
   && rm -rf /var/lib/apt/lists/*