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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


- Sets maximum speed (in MB/s) for migrations.
      - A value of 0 is no limit.
  name:
    description:
      - Specifies the VM name. Only used on the configuration web interface.
      - Required only for C(state=present).
  net:
    description:
      - A hash/dictionary of network interfaces for the VM. C(net='{"key":"value", "key":"value"}').
      - Keys allowed are - C(net[n]) where 0 ≤ n ≤ N.
      - Values allowed are - C("model="XX:XX:XX:XX:XX:XX",bridge="value",rate="value",tag="value",firewall="1|0",trunks="vlanid"").
      - Model is one of C(e1000 e1000-82540em e1000-82544gc e1000-82545em i82551 i82557b i82559er ne2k_isa ne2k_pci pcnet rtl8139 virtio vmxnet3).
      - C(XX:XX:XX:XX:XX:XX) should be an unique MAC address. This is automatically generated if not specified.
      - The C(bridge) parameter can be used to automatically add the interface to a bridge device. The Proxmox VE standard bridge is called 'vmbr0'.
      - Option C(rate) is used to limit traffic bandwidth from and to this interface. It is specified as floating point number, unit is 'Megabytes per second'.
      - If you specify no bridge, we create a kvm 'user' (NATed) network device, which provides DHCP and DNS services.
  newid:
    description:
      - VMID for the clone. Used only with clone.
      - If newid is not set, the next available VM ID will be fetched from ProxmoxAPI.
  node:
    description:
      - Proxmox VE node, where the new VM will be created.
      - Only required for C(state=present).
      - For other states, it will be autodiscovered.
  numa:
    description:
      - A hash/dictionaries of NUMA topology. C(numa='{"key":"value", "key":"value"}').
      - Keys allowed are - C(numa[n]) where 0 ≤ n ≤ N.
      - Values allowed are - C("cpu="<id[-id];...>",hostnodes="<id[-id];...>",memory="number",policy="(bind|interleave|preferred)"").