create, edit and use email branding instead of organisation

notable things that have been kept until migration is complete:

* passing in `organisation` to update_service will update email branding
* both `/email-branding` and `/organisation` hit the same code
* service endpoints still return organisation as well as email branding

app/organisation/organisation_schema.py

@@ -1,23 +0,0 @@
-post_create_organisation_schema = {
-    "$schema": "http://json-schema.org/draft-04/schema#",
-    "description": "POST schema for getting organisation",
-    "type": "object",
-    "properties": {
-        "colour": {"type": ["string", "null"]},
-        "name": {"type": ["string", "null"]},
-        "logo": {"type": ["string", "null"]}
-    },
-    "required": []
-}
-
-post_update_organisation_schema = {
-    "$schema": "http://json-schema.org/draft-04/schema#",
-    "description": "POST schema for getting organisation",
-    "type": "object",
-    "properties": {
-        "colour": {"type": ["string", "null"]},
-        "name": {"type": ["string", "null"]},
-        "logo": {"type": ["string", "null"]}
-    },
-    "required": []
-}

app/organisation/rest.py

@@ -1,51 +0,0 @@
-from flask import Blueprint, jsonify, request
-
-from app.dao.organisations_dao import (
-    dao_create_organisation,
-    dao_get_organisations,
-    dao_get_organisation_by_id,
-    dao_update_organisation
-)
-from app.errors import register_errors
-from app.models import Organisation
-from app.organisation.organisation_schema import post_create_organisation_schema, post_update_organisation_schema
-from app.schema_validation import validate
-
-organisation_blueprint = Blueprint('organisation', __name__)
-register_errors(organisation_blueprint)
-
-
-@organisation_blueprint.route('', methods=['GET'])
-def get_organisations():
-    organisations = [o.serialize() for o in dao_get_organisations()]
-    return jsonify(organisations=organisations)
-
-
-@organisation_blueprint.route('/<uuid:org_id>', methods=['GET'])
-def get_organisation_by_id(org_id):
-    organisation = dao_get_organisation_by_id(org_id)
-    return jsonify(organisation=organisation.serialize())
-
-
-@organisation_blueprint.route('', methods=['POST'])
-def create_organisation():
-    data = request.get_json()
-
-    validate(data, post_create_organisation_schema)
-
-    organisation = Organisation(**data)
-
-    dao_create_organisation(organisation)
-    return jsonify(data=organisation.serialize()), 201
-
-
-@organisation_blueprint.route('/<uuid:organisation_id>', methods=['POST'])
-def update_organisation(organisation_id):
-    data = request.get_json()
-
-    validate(data, post_update_organisation_schema)
-
-    fetched_organisation = dao_get_organisation_by_id(organisation_id)
-    dao_update_organisation(fetched_organisation, **data)
-
-    return jsonify(data=fetched_organisation.serialize()), 200