fix(dump) skip Developer Portal credentials in Kong Enterprise

Kong Enterprise Developer Portal exposes the credentials (basic/key) of
Developers on the Admin API, but doesn't expose the consumers causing
issues during export.

The root cause here is in Kong Enterprise but to help out decK users,
I'm going to put a work-around into decK.

The fix here is that for any basic and key auth credential, if the
associated consumer is not found by decK, it will not be exported.

Fix #75

dump/dump.go

@@ -75,7 +75,7 @@ func GetState(client *kong.Client, config Config) (*state.KongState, error) {
  if err != nil {
  // key could belong to a consumer which is not part
  // of this sub-set of the entire data-base
- if err == state.ErrNotFound && len(config.SelectorTags) > 0 {
+ if err == state.ErrNotFound {
  continue
  }
  return nil, errors.Wrapf(err,
@@ -129,7 +129,7 @@ func GetState(client *kong.Client, config Config) (*state.KongState, error) {
  if err != nil {
  // key could belong to a consumer which is not part
  // of this sub-set of the entire data-base
- if err == state.ErrNotFound && len(config.SelectorTags) > 0 {
+ if err == state.ErrNotFound {
  continue
  }
  return nil, errors.Wrapf(err,