Stanza's sentencizer only works when `processors = 'tokenize,pos,lemma,depparse'`

Hi all,

I started an NLP project where I needed high accuracy sentence segmentation, and therefore decided to use stanza.

I was thrilled to find this library, since Spacy is quite intuitive. However, I found that the sentence segmentation only gets carried into spacy under certain conditions.

**Baseline:**

The baseline text is to use the Stanza model alone to see if the sentence segmentation works.

This is the simplest model that I could use, I simply turned on the `tokenize` processor.

**Test with Spacy-Stanza:**

I then tried the same thing, but this time added the spacy-stanza wrapper.

As shown above, the sentences were not actually tokenized.

**Test with spacy-stanza with more processors on Stanza:**

It seems that the `depparse` processor is necessary, but this is rather confusing since the vanilla stanza model does not require it to tokenize.

Any help would be appreciated :)