Return the file path of the nearest drake
cache (searching upwards for directories containing a drake cache).
Only works if the cache is a file system in a
hidden folder named .drake.
Usage
find_cache(path = getwd(), target = NULL)
Arguments
path
starting path for search back for the cache.
Should be a subdirectory of the drake project.
target
Name of the folder containing the cache.
Value
File path of the nearest drake cache or NULL
if no cache is found.