unicode-casing: specify rev explicitly, add todo comment

Author: OddCoincidence

Cargo.lock

@@ -23,8 +23,12 @@ regex = "1"
 rustc_version_runtime = "0.1.*"
 statrs = "0.10.0"
 caseless = "0.2.1"
-unicode-casing = { git = "https://github.com/OddCoincidence/unicode-casing" }
 unicode-segmentation = "1.2.1"
 lazy_static = "^1.0.1"
 lexical = "2.0.0"
 itertools = "^0.8.0"
+
+# TODO: release and publish to crates.io
+[dependencies.unicode-casing]
+git = "https://github.com/OddCoincidence/unicode-casing"
+rev = "90d6d1f02b9cc04ffb55a5f1c3fa1455a84231fb"