enhancement: Remove mmh3 external dependency and use internal pymmh3 in place (#362)

Summary
-------
-  Removal of mmh3 external dependency and update imports to use internal pymmh3 instead

Testing
-------
- FSC

Issues
-------
- "OASIS-7995"

Author: The-inside-man

optimizely/bucketer.py

@@ -13,10 +13,7 @@
 
 import math
 
-try:
-    import mmh3
-except ImportError:
-    from .lib import pymmh3 as mmh3
+from .lib import pymmh3 as mmh3
 
 
 MAX_TRAFFIC_VALUE = 10000

requirements/core.txt

@@ -1,6 +1,5 @@
 jsonschema==3.2.0
 pyrsistent==0.16.0
-mmh3==2.5.1
 requests>=2.21
 pyOpenSSL>=19.1.0
 cryptography>=2.8.0

tests/test_bucketing.py

@@ -12,15 +12,14 @@
 # limitations under the License.
 
 import json
-import mmh3
 import mock
 import random
 
 from optimizely import bucketer
 from optimizely import entities
 from optimizely import logger
 from optimizely import optimizely
-from optimizely.lib import pymmh3
+from optimizely.lib import pymmh3 as mmh3
 
 from . import base
 
@@ -215,7 +214,7 @@ def test_hash_values(self):
 
         for i in range(10):
             random_value = str(random.random())
-            self.assertEqual(mmh3.hash(random_value), pymmh3.hash(random_value))
+            self.assertEqual(mmh3.hash(random_value), mmh3.hash(random_value))
 
 
 class BucketerWithLoggingTest(base.BaseTest):