add user_to_organisation and invited_organisation_users tables

similar to user_to_service and invited_users, but without auth types
or permissions

tests/conftest.py

@@ -4,7 +4,6 @@ import os
 from flask import Flask
 from alembic.command import upgrade
 from alembic.config import Config
-import boto3
 import pytest
 import sqlalchemy
 
@@ -128,12 +127,6 @@ def os_environ():
     os.environ = old_env
 
 
-@pytest.fixture(scope='function')
-def sqs_client_conn():
-    boto3.setup_default_session(region_name='eu-west-1')
-    return boto3.resource('sqs')
-
-
 def pytest_generate_tests(metafunc):
     # Copied from https://gist.github.com/pfctdayelise/5719730
     idparametrize = getattr(metafunc.function, 'idparametrize', None)