Spacy Text classification (Binary Classification)
You're very close to having a working script. The textcat training example in the spacy repository shows how to save the model, reload it, and run it on a new text: https://github.com/explosion/spaCy/blob/master/examples/training/train_textcat.py

From around line 103:

    # test the trained model
    test_text = "This movie sucked"
    doc = nlp(test_text)
    print(test_text, doc.cats)

    if output_dir is not None:
        with nlp.use_params(optimizer.averages):
            nlp.to_disk(output_dir)
        print("Saved model to", output_dir)

        # test the saved model
        print("Loading from", output_dir)
        nlp2 = spacy.load(output_dir)
        doc2 = nlp2(test_text)
        print(test_text, doc2.cats)
```