Removed one more utils reference in the README and fixed directory name

Signed-off-by: Carlo Costino <carlo.costino@gsa.gov>

tests/notifications_utils/test_base64_uuid.py

@@ -0,0 +1,57 @@
+import binascii
+import os
+from uuid import UUID
+
+import pytest
+
+from notifications_utils.base64_uuid import (
+    base64_to_bytes,
+    base64_to_uuid,
+    bytes_to_base64,
+    uuid_to_base64,
+)
+
+
+def test_bytes_to_base64_to_bytes():
+    b = os.urandom(32)
+    b64 = bytes_to_base64(b)
+    assert base64_to_bytes(b64) == b
+
+
+@pytest.mark.parametrize(
+    "url_val",
+    [
+        "AAAAAAAAAAAAAAAAAAAAAQ",
+        "AAAAAAAAAAAAAAAAAAAAAQ=",  # even though this has invalid padding we put extra =s on the end so this is okay
+        "AAAAAAAAAAAAAAAAAAAAAQ==",
+    ],
+)
+def test_base64_converter_to_python(url_val):
+    assert base64_to_uuid(url_val) == UUID(int=1)
+
+
+@pytest.mark.parametrize(
+    "python_val", [UUID(int=1), "00000000-0000-0000-0000-000000000001"]
+)
+def test_base64_converter_to_url(python_val):
+    assert uuid_to_base64(python_val) == "AAAAAAAAAAAAAAAAAAAAAQ"
+
+
+@pytest.mark.parametrize(
+    "url_val,expectation",
+    [
+        (
+            "this_is_valid_base64_but_is_too_long_to_be_a_uuid",
+            pytest.raises(binascii.Error),
+        ),
+        ("this_one_has_emoji_➕➕➕", pytest.raises(UnicodeEncodeError)),
+    ],
+)
+def test_base64_converter_to_python_raises_validation_error(url_val, expectation):
+    with expectation:
+        base64_to_uuid(url_val)
+
+
+def test_base64_converter_to_url_raises_validation_error():
+    with pytest.raises(AttributeError):
+        uuid_to_base64(object())