Class RouteCache

Route cache

Ideally we should use ACPu for caching, but it can be inconvenient to install, esp. on Windows1, thus we implement a naive file based cache.

Namespace: LeanCloud
Located at LeanCloud/AppRouter.php

Methods summary
`public static`	# `create( $id )`
`public`	# `write( $array )` Serialize array and store in file, array must be json_encode safe. Serialize array and store in file, array must be json_encode safe.
`public`	# `read( )` Read routes either from cache or file, return json_decoded array. Read routes either from cache or file, return json_decoded array.