Unit test added

This release contains a unit test and fix for ignoring the IAT check.

ignore iat validation failures - module name case fixed

Ignores iat validation failures.
Module name in go.mod changed to all lower-case.

ignore iat validation failures - has module name correction

Clock drift results in iat validation failures that can be safely ignored.
Module name corrected from github.com/NetApp/go-jwt-middleware to github.com/NetApp-Polaris/go-jwt-middleware.

ignore iat validation failures

Due to clock drift, iat validation can unnecessarily fail. This version ignores failed iat validations.