Add Tesco Store Seeder

[davidpiesse]

Only to be pulled in if Tesco is a viable option! Part of #11

[MiniCodeMonkey]

Fantastic!! Will hold on with merging until we can get a store scanner in place as well. Dealing with login required is of course not ideal, but here's an example of another chain that requires login: https://github.com/MiniCodeMonkey/curbside/blob/master/app/HarrisTeeterStoreScanner.php