Update retryOnAwsCode to Five Minutes (#999)

Users have been experiencing errors being returned on successful spaces create requests that take longer than 1 minute. Github issue is #996 

The only child function that `resourceDigitalOceanBucketCreate` using a 1 minute timeout is the `retryOnAwsCode` so updating that to 5 minutes to hopefully mitigate the errors on successful bucket creations.

digitalocean/spaces/resource_spaces_bucket.go

@@ -751,7 +751,7 @@ func BucketEndpoint(region string) string {
 
 func retryOnAwsCode(code string, f func() (interface{}, error)) (interface{}, error) {
  var resp interface{}
- err := resource.Retry(1*time.Minute, func() *resource.RetryError {
+ err := resource.Retry(5*time.Minute, func() *resource.RetryError {
  var err error
  resp, err = f()
  if err != nil {