resource/cloudflare_record: handle updating for records with data

[jacobbednarz]

Fixes the Update to respect the []interface{}s for the 3.x data
block.

Closes #1227

[jacobbednarz]

acceptance tests are passing

==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test $(go list ./...) -v -run "^TestAccCloudflareRecord_" -count 1 -parallel 1 -timeout 120m -parallel 1
?   	github.com/cloudflare/terraform-provider-cloudflare	[no test files]
=== RUN   TestAccCloudflareRecord_Import
--- PASS: TestAccCloudflareRecord_Import (15.36s)
=== RUN   TestAccCloudflareRecord_Basic
=== PAUSE TestAccCloudflareRecord_Basic
=== RUN   TestAccCloudflareRecord_CaseInsensitive
=== PAUSE TestAccCloudflareRecord_CaseInsensitive
=== RUN   TestAccCloudflareRecord_Apex
=== PAUSE TestAccCloudflareRecord_Apex
=== RUN   TestAccCloudflareRecord_LOC
=== PAUSE TestAccCloudflareRecord_LOC
=== RUN   TestAccCloudflareRecord_SRV
=== PAUSE TestAccCloudflareRecord_SRV
=== RUN   TestAccCloudflareRecord_CAA
=== PAUSE TestAccCloudflareRecord_CAA
=== RUN   TestAccCloudflareRecord_Proxied
=== PAUSE TestAccCloudflareRecord_Proxied
=== RUN   TestAccCloudflareRecord_Updated
=== PAUSE TestAccCloudflareRecord_Updated
=== RUN   TestAccCloudflareRecord_typeForceNewRecord
=== PAUSE TestAccCloudflareRecord_typeForceNewRecord
=== RUN   TestAccCloudflareRecord_hostnameForceNewRecord
=== PAUSE TestAccCloudflareRecord_hostnameForceNewRecord
=== RUN   TestAccCloudflareRecord_CreateAfterManualDestroy
=== PAUSE TestAccCloudflareRecord_CreateAfterManualDestroy
=== RUN   TestAccCloudflareRecord_TtlValidation
=== PAUSE TestAccCloudflareRecord_TtlValidation
=== RUN   TestAccCloudflareRecord_ExplicitProxiedFalse
=== PAUSE TestAccCloudflareRecord_ExplicitProxiedFalse
=== RUN   TestAccCloudflareRecord_MXWithPriorityZero
=== PAUSE TestAccCloudflareRecord_MXWithPriorityZero
=== RUN   TestAccCloudflareRecord_TtlValidationUpdate
=== PAUSE TestAccCloudflareRecord_TtlValidationUpdate
=== CONT  TestAccCloudflareRecord_Basic
--- PASS: TestAccCloudflareRecord_Basic (11.22s)
=== CONT  TestAccCloudflareRecord_typeForceNewRecord
--- PASS: TestAccCloudflareRecord_typeForceNewRecord (21.80s)
=== CONT  TestAccCloudflareRecord_TtlValidationUpdate
--- PASS: TestAccCloudflareRecord_TtlValidationUpdate (15.40s)
=== CONT  TestAccCloudflareRecord_MXWithPriorityZero
--- PASS: TestAccCloudflareRecord_MXWithPriorityZero (12.54s)
=== CONT  TestAccCloudflareRecord_ExplicitProxiedFalse
--- PASS: TestAccCloudflareRecord_ExplicitProxiedFalse (28.99s)
=== CONT  TestAccCloudflareRecord_TtlValidation
--- PASS: TestAccCloudflareRecord_TtlValidation (5.48s)
=== CONT  TestAccCloudflareRecord_CreateAfterManualDestroy
--- PASS: TestAccCloudflareRecord_CreateAfterManualDestroy (20.81s)
=== CONT  TestAccCloudflareRecord_hostnameForceNewRecord
--- PASS: TestAccCloudflareRecord_hostnameForceNewRecord (21.26s)
=== CONT  TestAccCloudflareRecord_Proxied
--- PASS: TestAccCloudflareRecord_Proxied (11.45s)
=== CONT  TestAccCloudflareRecord_Updated
--- PASS: TestAccCloudflareRecord_Updated (20.16s)
=== CONT  TestAccCloudflareRecord_CAA
--- PASS: TestAccCloudflareRecord_CAA (20.07s)
=== CONT  TestAccCloudflareRecord_Apex
--- PASS: TestAccCloudflareRecord_Apex (11.89s)
=== CONT  TestAccCloudflareRecord_LOC
--- PASS: TestAccCloudflareRecord_LOC (11.50s)
=== CONT  TestAccCloudflareRecord_CaseInsensitive
--- PASS: TestAccCloudflareRecord_CaseInsensitive (16.82s)
=== CONT  TestAccCloudflareRecord_SRV
--- PASS: TestAccCloudflareRecord_SRV (11.60s)
PASS
ok  	github.com/cloudflare/terraform-provider-cloudflare/cloudflare	256.977s
?   	github.com/cloudflare/terraform-provider-cloudflare/version	[no test files]

[innovate-invent]

Hi @jacobbednarz , when do you think 3.2.0 will be pushed to the registry?