added initial docker setup for running NGAS locally

ci/psql/Dockerfile.db

 FROM postgres:12.6-alpine
 
-COPY ./ci/psql/test_data_archive.sql.gz /docker-entrypoint-initdb.d/test_data_archive.sql.gz
+ARG NGAS_VERSION=11.0.2
+
+WORKDIR /repos
+
+RUN apk add git && \
+    git clone --depth 1 --branch "v${NGAS_VERSION}" https://github.com/ICRAR/ngas.git
+
+WORKDIR /
+
+COPY ./ci/psql/init_ngas_db.sh ./ci/psql/test_data_archive.sql.gz /docker-entrypoint-initdb.d/
 
 CMD ["postgres"]
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