Add cloudflare_account_roles data source

[ouranos]

Closes #1161

I'm not experienced with Go and didn't want to run make testacc against our account so I'm not too sure about the tests.
However, I've tested with the terraform snippet I used in the documentation and it's working as expected.

I haven't mapped the permissions field but this would be enough for the use case mentioned in #1161.

[jacobbednarz]

solid start! can you please also:

• add a changelog entry (using the changelog process)?
• add the datasource to the docs navigation: https://github.com/cloudflare/terraform-provider-cloudflare/blob/master/website/cloudflare.erb#L25

[ouranos]

Applied feedback. Let me know if I need to do anything else and if you want me to squash the commits.

[jacobbednarz]

Suggested change

	<li<%= sidebar_current("docs-cloudflare-account-roles") %>>
	<li<%= sidebar_current("docs-cloudflare-datasource-account-roles") %>>

[ouranos]

Is this line also incorrect then sidebar_current("docs-cloudflare-api-token-permission-groups") ?

[jacobbednarz]

no, the value in sidebar_current() needs to match the sidebar_current value in the YAML which this case does. they match and work but they should include datasource somewhere in the value but you don't have to worry about fixing that here.

[ouranos]

Let me know if I need to do anything else.

[jacobbednarz]

this looks good! acceptance tests are all passing locally!

==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test $(go list ./...) -v -run "^TestAccCloudflareAccountRoles" -count 1 -parallel 1 -timeout 120m -parallel 1
?   	github.com/cloudflare/terraform-provider-cloudflare	[no test files]
=== RUN   TestAccCloudflareAccountRoles
--- PASS: TestAccCloudflareAccountRoles (10.55s)
PASS
ok  	github.com/cloudflare/terraform-provider-cloudflare/cloudflare	11.069s
?   	github.com/cloudflare/terraform-provider-cloudflare/version	[no test files

[jacobbednarz]

solid effort on this one! thanks for your help getting this one over the line. 👏