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.
* Add SSH Keys to all droplets in tests, this prevents acctests from
spamming account owner email with root password details
* Add a new helper/acctest package to be a home for random string / int
implementations used in tests.
* Insert some random details into record tests to prevent collisions
* Normalize config style in tests to hclfmt conventions
Jake Champlin