Adds validation to cloudflare_record to ensure TTL is not set while proxied is true

[mrparkers]

Closes #126

Tests:

TF_ACC=1 go test $(go list ./... |grep -v 'vendor') -v -run=TestAccCloudflareRecord_TtlValidation* -timeout 120m
?   	github.com/terraform-providers/terraform-provider-cloudflare	[no test files]
=== RUN   TestAccCloudflareRecord_TtlValidation
=== PAUSE TestAccCloudflareRecord_TtlValidation
=== RUN   TestAccCloudflareRecord_TtlValidationUpdate
=== PAUSE TestAccCloudflareRecord_TtlValidationUpdate
=== CONT  TestAccCloudflareRecord_TtlValidation
=== CONT  TestAccCloudflareRecord_TtlValidationUpdate
--- PASS: TestAccCloudflareRecord_TtlValidation (0.02s)
--- PASS: TestAccCloudflareRecord_TtlValidationUpdate (3.71s)
PASS
ok  	github.com/terraform-providers/terraform-provider-cloudflare/cloudflare	3.738s

[jacobbednarz]

Initially I was thinking we should rely on ValidateFunc here to enforce this at a schema level however after some fiddling around, it seems it only has access to the current key and not the rest of the schema 😞

I'm 👍 with this approach providing we update the error message to be more accurate.

[mrparkers]

Yeah I agree that ValidateFunc could offer a lot more functionality. This is how I have seen it approached in other Terraform providers.

Also, that new "Suggested Change" feature is awesome. Thanks for not making me open my IDE to address your comments 😄

[jacobbednarz]

Awesome stuff! Thanks a bunch @mrparkers 🍰

[mrparkers]

I'm not sure I trust Travis since it reported a passing build when those tests probably should have failed. Here's a new snippet for test output with these changes:

==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test $(go list ./... |grep -v 'vendor') -v -run=TestAccCloudflareRecord_TtlValidation* -timeout 120m
?   	github.com/terraform-providers/terraform-provider-cloudflare	[no test files]
=== RUN   TestAccCloudflareRecord_TtlValidation
=== PAUSE TestAccCloudflareRecord_TtlValidation
=== RUN   TestAccCloudflareRecord_TtlValidationUpdate
=== PAUSE TestAccCloudflareRecord_TtlValidationUpdate
=== CONT  TestAccCloudflareRecord_TtlValidation
=== CONT  TestAccCloudflareRecord_TtlValidationUpdate
--- PASS: TestAccCloudflareRecord_TtlValidation (0.03s)
--- PASS: TestAccCloudflareRecord_TtlValidationUpdate (4.27s)
PASS
ok  	github.com/terraform-providers/terraform-provider-cloudflare/cloudflare	4.292s

[jacobbednarz]

Definitely worth digging into as I was thinking the same thing when the build came back green but had the incorrect assertions.

[patryk]

Thanks Michael and Jacob! We'll revisit tests if they become a problem.