Fix more tests

beeper node modules has a `return` statement outside of a function which doesn't parse. To fix it, we mock it. Also, setupEnvPolyfills is no longer being used.

Author: vjeux

jestSupport/setupEnvPolyfills.js

@@ -0,0 +1,5 @@
+// [email protected] has a return statement outside of a function
+// and therefore doesn't parse. Let's mock it so that we can
+// run the tests.
+
+module.exports = function () {};