108536490: Initial effort to implement log in

Add endpoint for post to /sign-in
Initialise role data

tests/app/main/test_encyption.py

@@ -0,0 +1,9 @@
+from app.main import encryption
+
+
+def test_encryption(notifications_admin):
+    value = 's3curePassword!'
+
+    encrypted = encryption.encrypt(value)
+
+    assert encrypted == encryption.encrypt(value)