Warning fixes

Development (#176)

* update login widget section in readme

* changing initializer to public (#171)

* Point to v4 (#173)

* Update to point to v4 + iss and aud validation
 Adds azp and issuer validation for V4

* Issue 2439 (#174)

Removed azp validation and updated tokens to v4 for tests

* bump up version to 6.0.0

* Issue 3201 (#177)

* update depandencies and fix warnings

* bump up version

* update xcode version