[Feature] - Marketplace support

[ddymko]

API was updated to allow support for deploying marketplace apps along with listing marketplace apps in the applications and upgrades endpoints for instances + bm

The applications list call now returns 3 new fields

• Type
• Vendor
• ImageID

https://www.vultr.com/api/#operation/list-applications

Instances and Baremetal have a new field called image_id in create + update

https://www.vultr.com/api/#operation/create-baremetal
https://www.vultr.com/api/#operation/update-baremetal

https://www.vultr.com/api/#operation/create-instance
https://www.vultr.com/api/#operation/update-instance

Also the upgrade list calls for instances and BM return the new fields for applications

https://www.vultr.com/api/#operation/get-instance-upgrades
https://www.vultr.com/api/#operation/get-bare-metals-upgrades