Support literal certificates

[julienduchesne]

Closes #273

10 minutes fix. Clearing out the clutter in the issues list :)

[github-actions]

In order to lower resource usage and have a faster runtime, PRs will not run Cloud tests automatically. To do so, a Grafana Labs employee must promote the Drone build.

For maintainers, it's better to run only the Cloud tests you need, rather than all of them. You can do so by setting the following parameter when promoting:

TESTARGS='-run=<testname>'

[lornest]

Hey @julienduchesne - one from the archives for you! Sorry 😅 . When I try this change passing in ca_cert as a literal, I get:

│   failed to create clients
│   with provider["registry.terraform.io/grafana/grafana"],
│   on main.tf line 10, in provider "grafana":
│   10: provider "grafana" {
│ open     -----BEGIN CERTIFICATE-----
| CERT BODY HERE
| -----END CERTIFICATE-----
│ : file name too long

Just wondering if I'm missing something with this change and how I'm passing the literal value for the cert? Passing like:

provider "grafana" {
  url     = "<url>"
  auth    = "<token>"
  ca_cert = <<EOS
    -----BEGIN CERTIFICATE-----
  CERT BODY HERE
    -----END CERTIFICATE-----
EOS
}