Id profId = [SELECT Id FROM Profile WHERE Name = 'Community Knowledge User' LIMIT 1].Id;
Account a = new Account(Name = 'Test5');
insert a;
Contact c = new Contact(AccountId = a.Id,
                       FirstName = 'Morgan',
                       LastName = 'Ma',
                       Email = 'testusr5@test.ourwebsite.com',
                       Title__c = 'Administrator');
insert c;
User u = new User(ContactId = c.Id,
                  Alias = 'MSstA5',
                 FirstName = c.FirstName,
                 LastName = c.LastName,
                 Email = c.Email,
                 Username = c.Email,
                 ProfileId = profId,
                 EmailEncodingKey = 'ISO-8859-1',
                 LanguageLocaleKey = 'en_US',
                 LocaleSidKey = 'en_US',
                 TimeZoneSidKey = 'America/New_York');
insert u;
System.setPassword(u.Id, 'Welcome1*');