Update dependency backoff to v2

Author: Renovate Bot

pyproject.toml

@@ -30,7 +30,7 @@ bs4 = "^0.0.1"
 lxml = "^4.6.2"
 geopy = "^2.1.0"
 tzwhere = "^3.0.3"
-backoff = "^1.11.1"
+backoff = "^2.0.0"
 
 [tool.poetry.dev-dependencies]
 pytest = "^6.2.2"