Add health check to pgsql docker image

.dockerignore

@@ -0,0 +1,2 @@
+.git
+.idea

.gitignore

@@ -0,0 +1 @@
+.idea/

pgsql/Dockerfile

@@ -13,6 +13,7 @@ EXPOSE 5432
 VOLUME /var/lib/postgresql/
 COPY pg_hba.conf /etc/postgresql/9.6/main/pg_hba.conf
 COPY startup.sh /srv/
+HEALTHCHECK CMD pg_isready -d postgres
 
 ENTRYPOINT ["dumb-init"]
 CMD "/srv/startup.sh"