Bug fixes (#427)

* Call the base container entrypoint with proper arguments

* Build the app container using path to directory

* Add CONTRIBUTING.md

db/entrypoint.sh

@@ -58,5 +58,5 @@ if [ "$1" = 'postgres' ]; then
   update_conf $wal_enable
 
   # Run the postgresql entrypoint
-  . /docker-entrypoint.sh
+  docker-entrypoint.sh postgres
 fi