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##### SUMMARY
An hour ago I upgraded my Proxmox to the new stable version 6. Since then my playbooks fail with this error:
`fatal: [proxmox]: FAILED! => {"changed": false, "msg": "authorization on proxmox cluster failed with exception: could not convert string to float: '6.0-4'"}`

It seems like the proxmox changed the API.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
proxmox (https://github.com/mrdrogdrog/ansible/blob/6430205d396b7c1733de22a898c51823f67d5bf4/lib/ansible/modules/cloud/misc/proxmox.py#L484)

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```
ansible 2.8.2
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/tilman/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3.7/site-packages/ansible
  executable location = /usr/bin/ansible
  python version = 3.7.3 (default, Jun 24 2019, 04:54:02) [GCC 9.1.0]
```


##### OS / ENVIRONMENT
Proxmox 6 


##### STEPS TO REPRODUCE
- Use the latest ansible version
- Use the latest stable version of proxmox (6)
- Use the proxmox module to do anything. E.g. create a container
- Get the error


##### EXPECTED RESULTS
Normal runthrough

##### ACTUAL RESULTS
Crash with an error


- Used only with clone
    type: bool
    default: 'yes'
  hostpci:
    description:
      - Specify a hash/dictionary of map host pci devices into guest. C(hostpci='{"key":"value", "key":"value"}').
      - Keys allowed are - C(hostpci[n]) where 0 ≤ n ≤ N.
      - Values allowed are -  C("host="HOSTPCIID[;HOSTPCIID2...]",pcie="1|0",rombar="1|0",x-vga="1|0"").
      - The C(host) parameter is Host PCI device pass through. HOSTPCIID syntax is C(bus:dev.func) (hexadecimal numbers).
      - C(pcie=boolean) I(default=0) Choose the PCI-express bus (needs the q35 machine model).
      - C(rombar=boolean) I(default=1) Specify whether or not the device's ROM will be visible in the guest's memory map.
      - C(x-vga=boolean) I(default=0) Enable vfio-vga device support.
      - /!\ This option allows direct access to host hardware. So it is no longer possible to migrate such machines - use with special care.
  hotplug:
    description:
      - Selectively enable hotplug features.
      - This is a comma separated list of hotplug features C('network', 'disk', 'cpu', 'memory' and 'usb').
      - Value 0 disables hotplug completely and value 1 is an alias for the default C('network,disk,usb').
  hugepages:
    description:
      - Enable/disable hugepages memory.
    choices: ['any', '2', '1024']
  ide:
    description:
      - A hash/dictionary of volume used as IDE hard disk or CD-ROM. C(ide='{"key":"value", "key":"value"}').
      - Keys allowed are - C(ide[n]) where 0 ≤ n ≤ 3.
      - Values allowed are - C("storage:size,format=value").
      - C(storage) is the storage identifier where to create the disk.
      - C(size) is the size of the disk in GB.
      - C(format) is the drive's backing file's data format. C(qcow2|raw|subvol).