Fix postres-hstore build

Dockerfile

@@ -5,6 +5,6 @@ WORKDIR /code
 RUN apt-get -y update
 RUN apt-get -y install libsasl2-dev libldap2-dev libssl-dev
 ADD requirements.txt /code/
-RUN pip install -r requirements.txt
+RUN pip install --no-cache-dir -r requirements.txt
 RUN wget https://github.com/vishnubob/wait-for-it/raw/8ed92e8cab83cfed76ff012ed4a36cef74b28096/wait-for-it.sh -O /usr/local/bin/wait-for-it && chmod +x /usr/local/bin/wait-for-it
 ADD . /code/

postgres-hstore/Dockerfile

@@ -1,3 +1,3 @@
 FROM postgres:latest
 MAINTAINER Piotr Dobrowolski
-ADD create_extension.sh docker-entrypoint-initdb.d/create_extension.sh
+ADD create_extension.sh /docker-entrypoint-initdb.d/create_extension.sh

postgres-hstore/create_extension.sh

@@ -1,9 +1,12 @@
+#!/bin/bash
+set -e
+
 # Because both template1 and the user postgres database have already been created,
 # we need to create the hstore extension in template1 and then recreate the postgres database.
 #
 # Running CREATE EXTENSION in both template1 and postgres can lead to
 # the extensions having different eid's.
-psql --dbname template1 <<EOSQL
+psql --dbname template1 -U postgres <<EOSQL
     CREATE EXTENSION hstore;
     CREATE EXTENSION ltree;
     DROP DATABASE $POSTGRES_USER;