Sanitize Docker-Compose provider project name

[Venthe]

Docker compose project name does not allow upper case characters. By default, Vagrant uses the current working directory as project name, and as such there can exist upper-case characters.

As an alternative, one can use COMPOSE_PROJECT_NAME environment variable to override Vagrant behaviour.

See:

• https://docs.docker.com/compose/reference/envvars/#compose_project_name

[hashicorp-cla]

All committers have signed the CLA.

[Venthe]

Please note, I am not a Ruby developer - this is a suggestion how to solve this issue in a way that is transparent for the end-user. As such, I have no knowledge how to proceed with writing the tests for it, though the setup should be simple:

# Pseudocode
# given
env.cwd = "Sample"
#  when
command = compose_execute(env)
# then
assert(command).switch_value("-p").is_equal_to("sample")

Alternatively, we could expand the documentation about the project name env variable