Add support for ECDSA and ED25519 keys

[josacar]

Description

Adds suport for ed25519 and ecdsa elliptic curve host keys as they are safer and shorter.

Development tasks

• Create a default serverspec suite
• Get ed25519 and ecdsa host keys before RSA and DSA keys
• Add key_type depending on the key
• Refactor search
• Fix separator
• Tight specs

  Check List

• [x] All tests pass. See https://github.com/chef-cookbooks/community_cookbook_documentation/blob/master/TESTING.MD
• [x] New functionality includes testing.
• [x] New functionality has been documented in the README if applicable
• [x] The CLA has been signed. See https://github.com/chef-cookbooks/community_cookbook_documentation/blob/master/CONTRIBUTING.MD

[josacar]

@tas50 Let me know if anything can be fixed or improved

[iennae]

HI @josacar, This looks pretty solid. The one thing is that it's still using the partial_search functionality from the partial_search cookbook. I'm going to go ahead and accept this, but if you have time and are willing could you investigate eliminating that dependency in a future PR? Thanks so much for your contribution.