Don't use `this` when testing ES5 variable export

We shouldn’t have to use `this`, because declaring a global variable in
ES5 should automatically be exported to the global namespace.
Add test for modules

This removes `import` because Meteor has already imported the file,
plus we don’t actually have the import path. This also changes the
string “1973” to an integer, because that’s how it’s defined in the
test setup.