add back JULIA_DEPOT_PATH make sure the first entry is default
in order for using IJulia
to just work out of the box, we need to expose the directory in JULIA_DEPOT_PATH but the first entry must be writable, thus the :
in order for using IJulia
to just work out of the box, we need to expose the directory in JULIA_DEPOT_PATH but the first entry must be writable, thus the :