provisioners/ansible: minor change in unit tests

Combine a maximum of options in the last test:
- Ansible Vault options from [GH-3338]
- raw_arguments

Note: it is not expected from Vagrant to reject incoherent combinations
provisioners/ansible: fix an error in a unit test
provisioners/ansible: Don't run with two --limits

Conflicts:
	test/unit/plugins/provisioners/ansible/provisioner_test.rb
provisioners/ansible: fix unit tests for [GH-3491]