pocket-lib--save-access-token doesn't create parent directories

[repelliuss]

with-temp-file in pocket-lib--save-access-token errors if file's directory does not exist. I encountered this issue in your pocket reader package. This leads an error to

pocket-lib--authorize: Opening output file: No such file or directory, c:/msys64/home/repelliuss/.cache/emacs-pocket-lib-token.json

on second call to pocket-reader which is not obvious as after authorizing you think pocket-reader couldn't authorize and therefore couldn't create the file but the actual problem is .cache directory doesn't exist.

It may not be common in Linux systems but I also use MSYS2 environment so it may be a good idea to make sure ~/.cache directory exists or even ask to create it.