[test] Make tests work in older browsers
[test] Make tests work in older browsers

Prevents the context from being boxed when strict mode is not supported.

primus/eventemitter3,primus/eventemitter3,malyshevalex/eventemitter3,marlun78/eventemitter3,malyshevalex/eventemitter3,marlun78/eventemitter3,naoufal/eventemitter3,primus/eventemitter3,pawsong/eventemitter3,naoufal/eventemitter3,pawsong/eventemitter3