* Upgrade to terraform-plugin-sdk
After following the [guide](https://www.terraform.io/docs/extend/plugin-sdk.html#using-tf-sdk-migrator)
Check
```
▶ GO111MODULE=on tf-sdk-migrator check
Checking Go runtime version ...
Go version 1.12.10: OK.
Checking whether provider uses Go modules...
Go modules in use: OK.
Checking version of github.com/hashicorp/terraform-plugin-sdk to determine if provider was already migrated...
Checking version of github.com/hashicorp/terraform used in provider...
Terraform version 0.12.8: OK.
Checking whether provider uses deprecated SDK packages or identifiers...
No imports of deprecated SDK packages or identifiers: OK.
All constraints satisfied. Provider can be migrated to the new SDK.
```
Migrate
```
▶ GO111MODULE=on tf-sdk-migrator migrate
Checking Go runtime version ...
Go version 1.12.10: OK.
Checking whether provider uses Go modules...
Go modules in use: OK.
Checking version of github.com/hashicorp/terraform-plugin-sdk to determine if provider was already migrated...
Checking version of github.com/hashicorp/terraform used in provider...
Terraform version 0.12.8: OK.
Checking whether provider uses deprecated SDK packages or identifiers...
No imports of deprecated SDK packages or identifiers: OK.
All constraints satisfied. Provider can be migrated to the new SDK.
Rewriting provider go.mod file...
Rewriting SDK package imports...
Running `go mod tidy`...
Success! Provider is migrated to github.com/hashicorp/terraform-plugin-sdk v1.1.0.
It looks like this provider vendors dependencies. Don't forget to run `go mod vendor`.
Make sure to review all changes and run all tests.
```
* Fix build under go 1.13.x.
* Added importability for load balancer
* Added importability, go fmt'ed
* Added importability for DNS records
* added importability for certificates
* Added import notes for DNS records and load balancers
* Added import tests
* Added random int for test configs
* Added certificates for the test to import
* Fixed docs, added certificate importability on docs
* Make TestAccDigitalOceanCertificate_importBasic pass by reusing certificate generation from resource_digitalocean_certificate_test.go
* Fix importablity of Load Balancer Droplet droplet_ids.
* Revert "Added importability for DNS records"
This reverts commit 94b1f69fe756c862125d0b899d49eca74f7bd591.
* Remove mention of record imports in docs.
* Remove digitalocean/import_digitalocean_record_test.go