fix postgres ref link CONTRIBUTING guide and add pgcrypto extension

Author: cbaker6

CONTRIBUTING.md

@@ -112,7 +112,7 @@ Once you have babel running in watch mode, you can start making changes to parse
 
 If your pull request introduces a change that may affect the storage or retrieval of objects, you may want to make sure it plays nice with Postgres.
 
-* Run the tests against the postgres database with `PARSE_SERVER_TEST_DB=postgres PARSE_SERVER_TEST_DATABASE_URI=postgres://postgres:password@localhost:5432/parse_server_postgres_adapter_test_database npm run testonly`. You'll need to have postgres running on your machine and setup [appropriately](https://github.com/parse-community/parse-server/blob/master/.travis.yml#L43) or use [`Docker`](#run-a-parse-postgres-with-docker).
+* Run the tests against the postgres database with `PARSE_SERVER_TEST_DB=postgres PARSE_SERVER_TEST_DATABASE_URI=postgres://postgres:password@localhost:5432/parse_server_postgres_adapter_test_database npm run testonly`. You'll need to have postgres running on your machine and setup [appropriately](https://github.com/parse-community/parse-server/blob/c4aadc974aa37c9e1907ae7f5c86f5971884b6c1/.github/workflows/ci.yml#L167-L169) or use [`Docker`](#run-a-parse-postgres-with-docker).
 * The Postgres adapter has a special debugger that traces all the sql commands. You can enable it with setting the environment variable `PARSE_SERVER_LOG_LEVEL=debug`
 * If your feature is intended to only work with MongoDB, you should disable PostgreSQL-specific tests with:
 
@@ -135,7 +135,7 @@ If your pull request introduces a change that may affect the storage or retrieva
 [PostGIS images (select one with v2.2 or higher) on docker dashboard](https://hub.docker.com/r/postgis/postgis) is based off of the official [postgres](https://registry.hub.docker.com/_/postgres/) image and will work out-of-the-box (as long as you create a user with the necessary extensions for each of your Parse databases; see below). To launch the compatible Postgres instance, copy and paste the following line into your shell:
 
 ```
-docker run -d --name parse-postgres -p 5432:5432 -e POSTGRES_PASSWORD=password --rm postgis/postgis:11-3.0-alpine && sleep 20 && docker exec -it parse-postgres psql -U postgres -c 'CREATE DATABASE parse_server_postgres_adapter_test_database;' && docker exec -it parse-postgres psql -U postgres -c 'CREATE EXTENSION postgis;' -d parse_server_postgres_adapter_test_database && docker exec -it parse-postgres psql -U postgres -c 'CREATE EXTENSION postgis_topology;' -d parse_server_postgres_adapter_test_database
+docker run -d --name parse-postgres -p 5432:5432 -e POSTGRES_PASSWORD=password --rm postgis/postgis:11-3.0-alpine && sleep 20 && docker exec -it parse-postgres psql -U postgres -c 'CREATE DATABASE parse_server_postgres_adapter_test_database;' && docker exec -it parse-postgres psql -U postgres -c 'CREATE EXTENSION pgcrypto; CREATE EXTENSION postgis;' -d parse_server_postgres_adapter_test_database && docker exec -it parse-postgres psql -U postgres -c 'CREATE EXTENSION postgis_topology;' -d parse_server_postgres_adapter_test_database
 ```
 To stop the Postgres instance: