Curly braces are not handled

[stevelacey]

Curly braces are not handled

> globToRegExp('./resources/lang/{en,fr}/*.json')

Expected:

/^\.\/resources\/lang\/(en|fr)\/.*\.json$/

or (minimatch produces this):

/^(?:\.\/resources\/lang\/en\.json|\.\/resources\/lang\/fr\.json)$/

Actual:

/^\.\/resources\/lang\/\{en\,fr\}\/.*\.json$/