* contrib/terraform/exoscale: Rework SSH public keys
Exoscale has a few limitations with `exoscale_ssh_keypair` resources.
Creating several clusters with these scripts may lead to an error like:
```
Error: API error ParamError 431 (InvalidParameterValueException 4350): The key pair "lj-sc-ssh-key" already has this fingerprint
```
This patch reworks handling of SSH public keys. Specifically, we rely on
the more cloud-agnostic way of configuring SSH public keys via
`cloud-init`.
* contrib/terraform/exoscale: terraform fmt
* contrib/terraform/exoscale: Add terraform validate
* contrib/terraform/exoscale: Inline public SSH keys
The Terraform scripts need to install some SSH key, so that Kubespray
(i.e., the "Ansible part") can take over. Initially, we pointed the
Terraform scripts to `~/.ssh/id_rsa.pub`. This proved to be suboptimal:
Operators sharing responbility for a cluster risk unnecessarily replacing resources.
Therefore, it has been determined that it's best to inline the public
SSH keys. The chosen variable `ssh_public_keys` provides some uniformity
with `contrib/azurerm`.
* Fix Terraform Exoscale test
* Fix Terraform 0.14 test
In some environments, it might not be possible to ping the IP address
of the nodes, e.g., because ICMP echo is blocked.
This commit allows kubespray to be configured to disable the ping
check, while performing all other checks.
Cristian Klein