v0.12.3rc1

1: Removed the auto scaling code from layer0 api. Layer0 api no longer takes the responsibilities of scaling ecs instances for the environment.
2: Added the AWS auto scaling by using capacity providers.
3: Fixed the aws ecs service and task ARN format.
4: Added two parameters during the l0 environment creation for capacity provider. max_count and taget_cap_size
5: Added make build command in layer0 root folder. Regenerated mock file and decorator files.