Add test for beam parsing

spacy/tests/parser/test_beam_parse.py

@@ -0,0 +1,10 @@
+import spacy
+import pytest
+
+@pytest.mark.models
+def test_beam_parse():
+    nlp = spacy.load('en_core_web_sm')
+    doc = nlp(u'Australia is a country', disable=['ner'])
+    ents = nlp.entity(doc, beam_width=2)
+    print(ents)
+