* Use boxyhq/saml20
* use sign from saml20
* cleaned up GetKeyInfo
* cleaned up getPublicKeyPemFromCertificate
* cleaned up node-forge
* use hasValidSignature from saml20
* cleanup and update saml20 to the beta version
* throw an error if signature is not valid
* updated saml20
* Validate AuthnRequest signature skelton
* Code refactor: Move the base64decode to common method
* wip
* Add signature validation
* Read the keys from config
* Lock dep version
Co-authored-by: Deepak Prabhakara <deepak@boxyhq.com>