* Add hash tests

tests/test_hash_table.py

@@ -0,0 +1,18 @@
+import pytest
+
+from spacy._hashing import FixedTable
+
+
+def test_insert():
+    table = FixedTable(20)
+    table[5] = 10
+    assert table.bucket(5) == 5
+    assert table[4] == 0
+    assert table[5] == 10
+
+def test_clobber():
+    table = FixedTable(10)
+    table[9] = 1
+    assert table.bucket(9) == 9
+    assert table.bucket(19) == 9
+