Chore: replace EPPN with email

This PR fixes an error in PreauthUserDetailsProvider where EPPN was being passed to the constructor in place of email, an artifact of the email attribute not being delivered by Shib until recently.

Please review: @ahoffmann @weizhong-wang @KJOYNER

src/main/edu/wisc/doit/uwphps/preauth/PreauthUserDetailsProvider.php

@@ -40,7 +40,7 @@ class PreauthUserDetailsProvider extends UserDetailsProvider
                 getenv($this->mapAttribute(static::PVI)),
                 getenv($this->mapAttribute(static::FULL_NAME)),
                 explode(static::DELIMITER, getenv($this->mapAttribute(static::UDDS))),
-                getenv($this->mapAttribute(static::EPPN)),
+                getenv($this->mapAttribute(static::EMAIL)),
                 getenv($this->mapAttribute(static::SOURCE)),
                 getenv($this->mapAttribute(static::ISIS_EMPLID)),
                 getenv($this->mapAttribute(static::FIRST_NAME)),
@@ -52,7 +52,7 @@ class PreauthUserDetailsProvider extends UserDetailsProvider
                 getenv(static::PVI),
                 getenv(static::FULL_NAME),
                 getenv(static::UDDS),
-                getenv(static::EPPN),
+                getenv(static::EMAIL),
                 getenv(static::SOURCE),
                 getenv(static::ISIS_EMPLID),
                 getenv(static::FIRST_NAME),