withIntermediateDirectories:中间目录，设置true的时候，可以创建中间目录，false的无法创建且会崩溃，如果最终的文件夹存在也会崩溃，一般返回true吧
/* createDirectoryAtPath:withIntermediateDirectories:attributes:error: creates a directory at the specified path. If you pass 'NO' for createIntermediates, the directory must not exist at the time this call is made. Passing 'YES' for 'createIntermediates' will create any necessary intermediate directories. This method returns YES if all directories specified in 'path' were created and attributes were set. Directories are created with attributes specified by the dictionary passed to 'attributes'. If no dictionary is supplied, directories are created according to the umask of the process. This method returns NO if a failure occurs at any stage of the operation. If an error parameter was provided, a presentable NSError will be returned by reference.
This method replaces createDirectoryAtPath:attributes:
*/
@available(iOS 2.0, *)
open func createDirectory(atPath path: String, withIntermediateDirectories createIntermediates: Bool, attributes: [FileAttributeKey : Any]? = nil) throws