[SalesForce] “Required fields are missing: [ProfileId]: [ProfileId]” when running Apex Class Test for ChatterAnswersAuthProviderRegTest

I am conducting an Apex test for ChatterAnswersAuthProviderRegTest, as I run this test, I encounter the following error message.

System.DmlException: Insert failed. First exception on row 0; first error: REQUIRED_FIELD_MISSING, Required fields are missing: [ProfileId]: [ProfileId]

I am curious to know where to go about obtaining the the id of a Chatter Answers Profile. I have attempted to call ProfileId though it appears the profile Id's I have available do not seem to allow. Or any steps I need to take.

@isTest(SeeAllData=True)
private class ChatterAnswersAuthProviderRegTest {
    static testMethod void validateCreateUpdateUser() {
        User thisUser = [ select Id from User where Id = :UserInfo.getUserId() ];
        System.runAs ( thisUser ) {
            Auth.UserData userData = new Auth.UserData('testId', 'testFirst', 'testLast',
            'testFirst testLast', 'no-reply@salesforce.com', null, 'testuserlong', 'en_US', 'facebook',
            null, new Map{'language' => 'en_US'});
            ChatterAnswersAuthProviderRegistration reg = new ChatterAnswersAuthProviderRegistration();
            Profile[] p = [SELECT Id FROM Profile WHERE Name = 'System Administrator'];
            User[] adminUser = [SELECT Id, Firstname, Lastname FROM User WHERE IsActive = true and ProfileId =: p[0].Id LIMIT 1];
            reg.setSiteAdminUserId(adminUser[0].Id);
            User newUser = reg.createUser(null, userData);
            System.assert(newUser != null, 'A new user should have been created');
            System.assertEquals(newUser.Firstname, 'testFirst', 'First name should have been same');
            System.assertEquals(newUser.Lastname, 'testLast', 'Last name should have been same');
            System.assertEquals(newUser.Email, 'no-reply@salesforce.com', 'Email should have been same');

            Contact c = new Contact();
            c.AccountId = (newUser.Username.split('@'))[0];
            c.LastName = 'contactLast';
            insert(c);

            newUser.Alias = 'firstusr';
            newUser.TimeZoneSidKey = 'America/Los_Angeles';
            newUser.LocaleSidKey = 'en_US';
            newUser.EmailEncodingKey = 'UTF-8';
            newUser.LanguageLocaleKey = 'en_US';
            newUser.ContactId = c.Id;

            insert(newUser);


            Auth.UserData updateUserData = new Auth.UserData('testId', 'updatedFirst', 'updatedLast',
            'updatedFirst updatedLast', 'no-reply@new.salesforce.com', null, 'testuserlong', 'en_US', 'facebook',
            null, new Map{'language' => 'en_US'});
            reg.updateUser(newUser.Id, null, updateUserData);

            User dbUser =  [SELECT Id, Firstname, Lastname, Email FROM User WHERE Id = :newUser.Id];
            System.assertEquals(dbUser.Firstname, 'updatedFirst', 'First name should have been updated');
            System.assertEquals(dbUser.Lastname, 'updatedLast', 'Last name should have been updated');
            System.assertEquals(dbUser.Email, 'no-reply@new.salesforce.com', 'Email should have been updated');
        }
    }
}