Add make command to build schema as on CI

Makefile

@@ -41,6 +41,9 @@ require-version:
 	@if [ ! "$(version)" ]; then echo "Missing version to publish"; exit 1; fi
 	@git rev-parse $(version) >/dev/null 2>&1 && (echo "Version $(version) already exists on local git repo !" && exit 1) || true
 
+schema:
+	./arkindex/manage.py generateschema --generator_class arkindex.project.openapi.SchemaGenerator > schema.yml
+
 release:
 	$(eval version:=$(shell cat VERSION))
 	echo $(version)