Returns the last moditication date for a given path.
Grabs the last modification date for a given path.
The modification date will be returned as a UNIX timestamp (in ms).
mtime('/path/to/file/or/directory', [recursive], callback). If recursive is set to
truethe timestamp of the last modified file within that directory (including the directory itself) will be returned.
mtime.sync('/path', [recursive]). Does a sync op to find out the last modification date of the given path. Will throw any error that occurs.