Fix EC2 classic bootstrap

[josacar]

Description

Fixes the described scenario in #641

Related Issue

Fixes #641 641

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• I have read the CONTRIBUTING document.
• I have run the pre-merge tests locally and they pass.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• All commits have been signed-off for the Developer Certificate of Origin.

[josacar]

I haven't added tests for this bugfix, but I fixed the failing ones.

Let me know if you need me to add specific tests.

[tas50]

@josacar This is very cool. Can you sign the commit off for the DCO and see if there's anything you can do to test it.

[josacar]

@tas50 I've added a test for EIP attaching, but I cannot find any existing test for server_hashes function. Let me know what you think.

[josacar]

According to the docs, this mock should be wrong, and it should be group_name instead of name:

resp.reservations[0].groups #=> Array
resp.reservations[0].groups[0].group_name #=> String
resp.reservations[0].groups[0].group_id #=> String

[josacar]

I think this only makes sense to EC2 classic as VPC uses security_group_ids instead of groups

[josacar]

I've introduced instance_double as they raise an exception when a method does not exist in the mocked class, as opposite as Openstruct that returns nil. This makes less fragile tests as mocked classes evolve and mocks get obsolete.

[tas50]

Thanks for the tests @josacar