Add rapidfuzz existence test

Author: ryanholbrook

tests/test_rapidfuzz.py

@@ -0,0 +1,11 @@
+import unittest
+
+import rapidfuzz
+
+class TestRapidfuzz(unittest.TestCase):
+    def test_distance(self):
+        distance = rapidfuzz.distance.Levenshtein.distance(
+            'Levenshtein', 'Lenvinsten'
+        )
+
+        self.assertEqual(4, distance)