Upgrade to Wayback v0.2.4 (#631)

Mr0grog · web-flow · commit b91147c8cfe9 · 2020-09-07T13:11:04.000-07:00
It has a bunch of error handling improvements we want.
diff --git a/requirements.txt b/requirements.txt
@@ -14,4 +14,4 @@ requests ~=2.24.0
 toolz ~=0.10.0
 tornado ~=6.0.4
 tqdm ~=4.48.2
-wayback ~=0.2.3
+wayback ~=0.2.4
