bump CodeTracking compatibility to v2 (#658)

CodeTracking has been updated to the new major version v2, but since
Cthulhu is not affected by the breaking changes, we can just bump our
compat up to allow it.

Author: aviatesk

Project.toml

@@ -4,7 +4,7 @@ uuid = "f68482b8-f384-11e8-15f7-abe071a5a75f"
 version = "2.17.5"
 
 [compat]
-CodeTracking = "0.5, 1"
+CodeTracking = "0.5, 1, 2"
 Compiler = "0.1"
 FoldingTrees = "1"
 InteractiveUtils = "1.9"