merge postgres dockerfiles

Merge the two files build/postgres/Dockerfile and docker-compose/posgres/Dockerfile.
They have the same contents once we add the /wait-for-it script into the build Dockerfile.

refs DE-220
flag = none

Test plan:
- Ensure that ./script/docker_dev_setup.sh works correctly
- Ensure that Jenkins builds correctly when using the new PG image

Change-Id: I0e39ceb2f1ec7c9eacbe155f98af7fa78b0f9b8c
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/246898
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Aaron Ogata <aogata@instructure.com>
QA-Review: Andrea Cirulli <andrea.cirulli@instructure.com>
Product-Review: Ryan Norton <rnorton@instructure.com>
Product-Review: Aaron Ogata <aogata@instructure.com>

build/docker-compose/postgres/Dockerfile

@@ -1,40 +0,0 @@
-ARG POSTGRES=12
-FROM postgis/postgis:$POSTGRES-2.5
-
-RUN echo "max_locks_per_transaction = 640" >> /usr/share/postgresql/$PG_MAJOR/postgresql.conf.sample \
- && echo "max_stack_depth = 5MB" >> /usr/share/postgresql/$PG_MAJOR/postgresql.conf.sample \
- && echo "random_page_cost = 1.0" >> /usr/share/postgresql/$PG_MAJOR/postgresql.conf.sample \
- && echo "shared_buffers = 256MB" >> /usr/share/postgresql/$PG_MAJOR/postgresql.conf.sample \
- && echo "effective_cache_size = 256MB" >> /usr/share/postgresql/$PG_MAJOR/postgresql.conf.sample
-
-ENV PG_COLLKEY_VERSION 0.5.1
-
-RUN apt-get update --quiet=2 \
-  && apt-get install --quiet=2 \
-    build-essential \
-    ca-certificates \
-    libicu-dev \
-    postgresql-server-dev-$PG_MAJOR \
-    pgxnclient \
-    unzip \
-  && pgxnclient download --yes --target ~ pg_collkey=${PG_COLLKEY_VERSION} \
-  && unzip ~/pg_collkey-${PG_COLLKEY_VERSION}.zip -d ~/ \
-  && cd ~/pg_collkey-${PG_COLLKEY_VERSION} \
-  && mv Makefile Makefile.orig \
-  && sed '/^DATA = \$(wildcard/d' Makefile.orig > Makefile \
-  && make \
-  && make install \
-  && cp -v ~/pg_collkey-${PG_COLLKEY_VERSION}/pg_collkey--${PG_COLLKEY_VERSION}.sql /usr/share/postgresql/$PG_MAJOR/extension \
-  && apt-get remove -qqy \
-    build-essential \
-    ca-certificates \
-    libicu-dev \
-    postgresql-server-dev-$PG_MAJOR \
-    pgxnclient \
-    unzip \
-  && rm -rf \
-    /var/lib/apt/lists/* \
-    /tmp/* \
-    /var/tmp/*
-
-COPY /create-dbs.sh /docker-entrypoint-initdb.d/

build/docker-compose/postgres/create-dbs.sh

@@ -1,13 +0,0 @@
-#!/bin/bash
-
-set -o errexit -o errtrace -o nounset -o pipefail -o xtrace
-
-# install extension on template1 which every new database is built from,
-# so we don't have to run this more than once
-psql -v ON_ERROR_STOP=1 --username postgres <<SQL
-  \connect template1;
-  CREATE EXTENSION IF NOT EXISTS pg_trgm SCHEMA public;
-  CREATE EXTENSION IF NOT EXISTS postgis SCHEMA public;
-  CREATE EXTENSION IF NOT EXISTS pg_collkey SCHEMA public;
-  CREATE DATABASE canvas_test
-SQL