Fixes failing acceptance test:
```
$ make testacc TEST=./builtin/providers/digitalocean TESTARGS='-run=TestAccDigitalOceanVolume_Droplet'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
2017/01/20 11:38:26 Generated command/internal_plugin_list.go
TF_ACC=1 go test ./builtin/providers/digitalocean -v -run=TestAccDigitalOceanVolume_Droplet -timeout 120m
=== RUN TestAccDigitalOceanVolume_Droplet
--- PASS: TestAccDigitalOceanVolume_Droplet (57.38s)
PASS
ok github.com/hashicorp/terraform/builtin/providers/digitalocean 57.411s
```
Also removes all redundant type declarations in the digitalocean package.
```
make testacc TEST=./builtin/providers/digitalocean
TESTARGS='-run=TestAccDigitalOceanDomain_'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /vendor/)
TF_ACC=1 go test ./builtin/providers/digitalocean -v -run=TestAccDigitalOceanDomain_ -timeout 120m
=== RUN TestAccDigitalOceanDomain_importBasic
--- PASS: TestAccDigitalOceanDomain_importBasic (3.07s)
=== RUN TestAccDigitalOceanDomain_Basic
--- PASS: TestAccDigitalOceanDomain_Basic (1.99s)
PASS
ok github.com/hashicorp/terraform/builtin/providers/digitalocean
5.072s
```
The error string for 404s on DNS domains has (apparently)
changed, causing things to be a little sad when you modify
DNS domains from the DO console instead of terraform. This
is just the same fix as was applied to droplets around this
time last month.
While I was at it I just fixed this everywhere I saw it in the
DO provider source tree.
Jake Champlin