Postgres image is failing to build

[cer]

See https://circleci.com/gh/eventuate-tram/eventuate-tram-core/45

Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 libprotobuf-c-dev : Depends: libprotobuf-c1 (= 1.2.1-2) but 1.3.1-1 is to be installed
E: Unable to correct problems, you have held broken packages.
ERROR: Service 'postgres' failed to build: The command '/bin/sh -c apt-get update     && apt-get install -f -y --no-install-recommends         software-properties-common         build-essential         pkg-config         git         postgresql-server-dev-9.6         libproj-dev     && apt-get clean && apt-get update && apt-get install -f -y --no-install-recommends         liblwgeom-dev     && add-apt-repository "deb http://ftp.debian.org/debian testing main contrib"     && apt-get install nano     && apt-get update && apt-get install -f -y --no-install-recommends         libprotobuf-c-dev=1.2.*     && rm -rf /var/lib/apt/lists/*' returned a non-zero code: 100
Exited with code 1

[cer]

Todo:

• apt-get install cleanups, e.g. rm -rf /var/lib/apt/lists/*
• Upgrading to later commit for the wal2json plugin