Give me the brewery and brand names of canned root beer that were purchased before 6/6/2015.
canned root beer refers to ContainerType = 'Can'; purchased before 6/6/2015 refers to PurchaseDate < '2015-06-06';
SELECT DISTINCT T2.BreweryName, T2.BrandName FROM rootbeer AS T1 INNER JOIN rootbeerbrand AS T2 ON T1.BrandID = T2.BrandID WHERE T1.PurchaseDate < '2015-06-06' AND T1.ContainerType = 'Can'