CLOUDP-69270:Backup: atlas snapshots create

[andreaangiolillo]

Proposed changes

Jira ticket: CLOUDP-69270

Checklist

• I have signed the MongoDB CLA
• I have added tests that prove my fix is effective or that my feature works
• I have added any necessary documentation (if appropriate)
• I have run make fmt and formatted my code

Further comments

./bin/mongocli atlas backups snapshots create Cluster1 --desc test2 --retention 3
Snapshot '5f35178eb21554136479ff0c' created.

./bin/mongocli atlas backups snapshots create Cluster0 --desc test
Snapshot '5f3516d0c600162315976f7c' created.

./bin/mongocli atlas backups snapshots create Cluster0 --desc test2 --retention 3 -o "json"
{
  "id": "5f35185dc60016231597711d",
  "createdAt": "2020-08-13T10:39:25Z",
  "expiresAt": "2020-08-16T10:39:25Z",
  "description": "test2",
  "links": [
    {
      "rel": "self",
      "href": "https://cloud-dev.mongodb.com/api/atlas/v1.0/groups/5e4e593f70dfbf1010295836/clusters/Cluster0/backup/snapshots/5f35185dc60016231597711d"
    },
    {
      "rel": "http://mms.mongodb.com/cluster",
      "href": "https://cloud-dev.mongodb.com/api/atlas/v1.0/groups/5e4e593f70dfbf1010295836/clusters/Cluster0"
    }
  ],
  "mongodVersion": "4.2.8",
  "snapshotType": "onDemand",
  "status": "queued",
  "type": "replicaSet"
}

[gssbzn]

Left a couple of small comments, nothing major, this looks great

[gssbzn]

[nit] can we add "take" as an alias to match the GUI?

[gssbzn]

Suggested change

	// ContinuousSnapshots encapsulates the logic to manage different cloud providers
	// Snapshots encapsulates the logic to manage different cloud providers

[gssbzn]

👍

[gssbzn]

LGTM