bump version to 0.21.0 (#64)

Author: mrmauer

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "propelauth"
-version = "0.20.0"
+version = "0.21.0"
 authors = ["support@propelauth.com"]
 description = "A Rust crate for managing authentication and authorization with support for multi-tenant / B2B products, powered by PropelAuth"
 keywords = ["authentication", "auth", "authorization", "b2b", "tenant"]