Custom Errors to ErrorEPCs

[sajidanower23]

According to the specs, there are specified vocabulary for errors.
It is worth having a function that takes in the custom errors (ParseFailures) and returns a proper error based on the Vocabulary.

Original Author: ano002

(Moved with github-migration-0.1.0.0 (package github-migration-0.1.0.0 revision df9f38b))

[sajidanower23]

@fal05c Could you please document where in the specs the error vocabulary is listed?

Original Author: ano002