Quick correction for browser

[rymohr]

Too small for a pull request. To work in the browser this line has to be changed:

# currently
this.name = definition()

# should be
this[name] = definition();

Thanks for the library. Exactly what I was looking for!

[pimterry]

Ah yes, good catch! Thanks.

For the record, useful 1 line pull requests like this are totally fine 😄