ci: Run tests using postgres docker container (#715)

* use postgres docker for tests

* checkout repo

* add checkout

* remove secrets

db/run_postgres.sh

@@ -0,0 +1,10 @@
+# build container
+docker build -f db/Dockerfile.simple -t pg-test .
+
+# run container
+docker run -d --rm \
+   --name memgpt-db-test \
+   -p 8888:5432 \
+   -e POSTGRES_PASSWORD=password \
+   -v memgpt_db_test:/var/lib/postgresql/data \
+    pg-test:latest