Localize notification_utils to the admin

This changeset pulls in all of the notification_utils code directly into the admin and removes it as an external dependency. We are doing this to cut down on operational maintenance of the project and will begin removing parts of it no longer needed for the admin.

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

tests/notifications_utils/test_url_safe_tokens.py

@@ -0,0 +1,36 @@
+import urllib
+
+from itsdangerous import BadSignature, SignatureExpired
+from pytest import fail
+
+from notifications_utils.url_safe_token import check_token, generate_token
+
+
+def test_should_return_payload_from_signed_token():
+    payload = "email@something.com"
+    token = generate_token(payload, "secret-key", "dangerous-salt")
+    token = urllib.parse.unquote(token)
+    assert payload == check_token(token, "secret-key", "dangerous-salt", 30)
+
+
+def test_should_throw_exception_when_token_is_tampered_with():
+    import uuid
+
+    token = generate_token(str(uuid.uuid4()), "secret-key", "dangerous-salt")
+    try:
+        check_token(token + "qerqwer", "secret-key", "dangerous-salt", 30)
+        fail()
+    except BadSignature:
+        pass
+
+
+def test_return_none_when_token_is_expired():
+    max_age = -1000
+    payload = "some_payload"
+    token = generate_token(payload, "secret-key", "dangerous-salt")
+    token = urllib.parse.unquote(token)
+    try:
+        assert check_token(token, "secret-key", "dangerous-salt", max_age) is None
+        fail("Expected a SignatureExpired exception")
+    except SignatureExpired:
+        pass