TST: Add CI infrastructure for integration testing

See https://gitlab.indiscale.com/caosdb/customers/lfpb/management/-/issues/359. This MR only adds infrastructure for the triggering and set-up of the integration tests. The actual additions are in caosdb-juliainttest!1 (merged).

.docker/Dockerfile

 FROM julia:1.6
 
 RUN echo 'deb http://deb.debian.org/debian buster-backports main' > /etc/apt/sources.list.d/buster-backports.list
-RUN apt-get update && apt-get install -y git python3-pip
+RUN apt-get update
 RUN apt-get install -y cmake/buster-backports
+RUN apt-get install -y git
+RUN apt-get install -y python3-pip
+RUN apt-get install -y curl
+
+# Dirty workaround for java not linking to the correct manpage directory (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=863199)
+RUN mkdir -p /usr/share/man/man1
+RUN apt-get install -y openjdk-11-jdk-headless
 RUN pip3 install conan
 

[Florian Spreckelsen]

That's why we love debian, isn't it?