Imports-remote example has reference to non existent files

[bijenkins]

In the imports-remote example, the fixtures.tfvars variable file points to pages that return a 404 for map_config_* vars. The example should be updated for usability.

# https://github.com/cloudposse/terraform-yaml-config/blob/main/examples/imports-remote/fixtures.tfvars

enabled = true

map_config_remote_base_path = "https://raw.githubusercontent.com/cloudposse/atmos/master/example/stacks"

map_config_paths = [
  "https://raw.githubusercontent.com/cloudposse/atmos/master/example/stacks/ue2-prod.yaml"
]