provider/digitalocean: Update digital ocean acceptance tests

Digital Ocean doesn't let you upload multiple SSH keys regardless of key_name, but on the fingerprint of the key contents. Which broke all of our tests when ran in parallel.

These changes maintain our acctest validity, and still let them pass.

```
##teamcity[testStarted timestamp='2017-02-10T16:19:12.532' name='TestAccDigitalOceanDroplet_Basic']
##teamcity[testStdOut name='TestAccDigitalOceanDroplet_Basic' out='=== RUN   TestAccDigitalOceanDroplet_Basic|n--- PASS: TestAccDigitalOceanDroplet_Basic (47.33s)|nPASS|n']
##teamcity[testStdErr name='TestAccDigitalOceanDroplet_Basic' out='']
##teamcity[testFinished timestamp='2017-02-10T16:19:59.898' name='TestAccDigitalOceanDroplet_Basic']
##teamcity[testStarted timestamp='2017-02-10T16:19:12.532' name='TestAccDigitalOceanDroplet_UpdateTags']
##teamcity[testStdOut name='TestAccDigitalOceanDroplet_UpdateTags' out='=== RUN   TestAccDigitalOceanDroplet_UpdateTags|n--- PASS: TestAccDigitalOceanDroplet_UpdateTags (50.96s)|nPASS|n']
##teamcity[testStdErr name='TestAccDigitalOceanDroplet_UpdateTags' out='']
##teamcity[testFinished timestamp='2017-02-10T16:20:03.516' name='TestAccDigitalOceanDroplet_UpdateTags']
##teamcity[testStarted timestamp='2017-02-10T16:19:12.530' name='TestAccDigitalOceanDroplet_importBasic']
##teamcity[testStdOut name='TestAccDigitalOceanDroplet_importBasic' out='=== RUN   TestAccDigitalOceanDroplet_importBasic|n--- PASS: TestAccDigitalOceanDroplet_importBasic (56.78s)|nPASS|n']
##teamcity[testStdErr name='TestAccDigitalOceanDroplet_importBasic' out='']
##teamcity[testFinished timestamp='2017-02-10T16:20:09.335' name='TestAccDigitalOceanDroplet_importBasic']
##teamcity[testStarted timestamp='2017-02-10T16:19:12.530' name='TestAccDigitalOceanDroplet_PrivateNetworkingIpv6']
##teamcity[testStdOut name='TestAccDigitalOceanDroplet_PrivateNetworkingIpv6' out='=== RUN   TestAccDigitalOceanDroplet_PrivateNetworkingIpv6|n--- PASS: TestAccDigitalOceanDroplet_PrivateNetworkingIpv6 (57.60s)|nPASS|n']
##teamcity[testStdErr name='TestAccDigitalOceanDroplet_PrivateNetworkingIpv6' out='']
##teamcity[testFinished timestamp='2017-02-10T16:20:10.157' name='TestAccDigitalOceanDroplet_PrivateNetworkingIpv6']
##teamcity[testStarted timestamp='2017-02-10T16:19:12.533' name='TestAccDigitalOceanDroplet_withSSH']
##teamcity[testStdOut name='TestAccDigitalOceanDroplet_withSSH' out='=== RUN   TestAccDigitalOceanDroplet_withSSH|n--- PASS: TestAccDigitalOceanDroplet_withSSH (59.76s)|nPASS|n']
##teamcity[testStdErr name='TestAccDigitalOceanDroplet_withSSH' out='']
##teamcity[testFinished timestamp='2017-02-10T16:20:12.326' name='TestAccDigitalOceanDroplet_withSSH']
##teamcity[testStarted timestamp='2017-02-10T16:19:12.530' name='TestAccDigitalOceanDroplet_Update']
##teamcity[testStdOut name='TestAccDigitalOceanDroplet_Update' out='=== RUN   TestAccDigitalOceanDroplet_Update|n--- PASS: TestAccDigitalOceanDroplet_Update (83.65s)|nPASS|n']
##teamcity[testStdErr name='TestAccDigitalOceanDroplet_Update' out='']
##teamcity[testFinished timestamp='2017-02-10T16:20:36.213' name='TestAccDigitalOceanDroplet_Update']
##teamcity[testStarted timestamp='2017-02-10T16:19:12.530' name='TestAccDigitalOceanDroplet_UpdateUserData']
##teamcity[testStdOut name='TestAccDigitalOceanDroplet_UpdateUserData' out='=== RUN   TestAccDigitalOceanDroplet_UpdateUserData|n--- PASS: TestAccDigitalOceanDroplet_UpdateUserData (103.18s)|nPASS|n']
##teamcity[testStdErr name='TestAccDigitalOceanDroplet_UpdateUserData' out='']
##teamcity[testFinished timestamp='2017-02-10T16:20:55.738' name='TestAccDigitalOceanDroplet_UpdateUserData']
##teamcity[testStarted timestamp='2017-02-10T16:19:12.533' name='TestAccDigitalOceanDroplet_ResizeWithOutDisk']
##teamcity[testStdOut name='TestAccDigitalOceanDroplet_ResizeWithOutDisk' out='=== RUN   TestAccDigitalOceanDroplet_ResizeWithOutDisk|n--- PASS: TestAccDigitalOceanDroplet_ResizeWithOutDisk (118.98s)|nPASS|n']
##teamcity[testStdErr name='TestAccDigitalOceanDroplet_ResizeWithOutDisk' out='']
##teamcity[testFinished timestamp='2017-02-10T16:21:11.558' name='TestAccDigitalOceanDroplet_ResizeWithOutDisk']
```

builtin/providers/digitalocean/import_digitalocean_droplet_test.go

@@ -3,19 +3,21 @@ package digitalocean
 import (
 	"testing"
 
+	"github.com/hashicorp/terraform/helper/acctest"
 	"github.com/hashicorp/terraform/helper/resource"
 )
 
 func TestAccDigitalOceanDroplet_importBasic(t *testing.T) {
 	resourceName := "digitalocean_droplet.foobar"
+	rInt := acctest.RandInt()
 
 	resource.Test(t, resource.TestCase{
 		PreCheck:     func() { testAccPreCheck(t) },
 		Providers:    testAccProviders,
 		CheckDestroy: testAccCheckDigitalOceanDropletDestroy,
 		Steps: []resource.TestStep{
 			{
-				Config: testAccCheckDigitalOceanDropletConfig_basic,
+				Config: testAccCheckDigitalOceanDropletConfig_basic(rInt),
 			},
 
 			{

builtin/providers/digitalocean/import_digitalocean_floating_ip_test.go

@@ -3,6 +3,7 @@ package digitalocean
 import (
 	"testing"
 
+	"github.com/hashicorp/terraform/helper/acctest"
 	"github.com/hashicorp/terraform/helper/resource"
 )
 
@@ -29,14 +30,15 @@ func TestAccDigitalOceanFloatingIP_importBasicRegion(t *testing.T) {
 
 func TestAccDigitalOceanFloatingIP_importBasicDroplet(t *testing.T) {
 	resourceName := "digitalocean_floating_ip.foobar"
+	rInt := acctest.RandInt()
 
 	resource.Test(t, resource.TestCase{
 		PreCheck:     func() { testAccPreCheck(t) },
 		Providers:    testAccProviders,
 		CheckDestroy: testAccCheckDigitalOceanFloatingIPDestroy,
 		Steps: []resource.TestStep{
 			{
-				Config: testAccCheckDigitalOceanFloatingIPConfig_droplet,
+				Config: testAccCheckDigitalOceanFloatingIPConfig_droplet(rInt),
 			},
 
 			{

builtin/providers/digitalocean/import_digitalocean_ssh_key_test.go

@@ -15,7 +15,7 @@ func TestAccDigitalOceanSSHKey_importBasic(t *testing.T) {
 		CheckDestroy: testAccCheckDigitalOceanSSHKeyDestroy,
 		Steps: []resource.TestStep{
 			{
-				Config: testAccCheckDigitalOceanSSHKeyConfig_basic,
+				Config: testAccCheckDigitalOceanSSHKeyConfig_basic(testAccValidImportPublicKey),
 			},
 
 			{