Directory to scan
Wildcard to match (e.g. *.js)
Whether to scan recursively
[string] File names
scanDirectory('/path/to/dir', '*.js') // ['file1.js', 'file2.js', 'abc.js']
scanDirectory('/path/to/dir', 'file*.js, true) // ['file1.js', 'folder/file2.js']
Scan a directory for files matching a wildcard