Updates todo list.

Author: alokmenghrajani

Todo.md

@@ -11,4 +11,5 @@ TODO List
 * Make it easier to build a subset of the library. Some people might only want
   to do encryption or encryption with a specific algorithm.
 * Rethink error handling. Do we really need JoseJWE.assert?
-* Add support for importing public keys as PEM files and validating signatures.
+* Add support for importing public keys as PEM files and validating signatures.
+* Improve handling of malformed JSON input (see https://tools.ietf.org/html/draft-ietf-jose-json-web-signature-41#section-10.12)