Use PosixPath for path handling and create parent folders if they not exist

[CM000n]

This should fix an error if the parents of the CACHE_FILENAME do not exist in some environments.
See: #270

[codecov]

Codecov Report

Attention: 4 lines in your changes are missing coverage. Please review.

Comparison is base (6e651ed) 72.46% compared to head (652cda1) 72.46%.

Files	Patch %	Lines
mytoyota/controller.py	50.00%	4 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #271   +/-   ##
=======================================
  Coverage   72.46%   72.46%           
=======================================
  Files          28       28           
  Lines        1351     1351           
=======================================
  Hits          979      979           
  Misses        372      372           

Flag	Coverage Δ
unittests	72.46% <50.00%> (ø)

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[CM000n]

You should now have maintainer access @GitOldGrumpy 😊 Can you pls review this MR?

[GitOldGrumpy]

Looks good to me.

[CM000n]

Looks good to me.

Strange, merging ist still blocked :-/
Can you please approve these changes @GitOldGrumpy?

Have you received and accepted the Maintainer invitation E-Mail?
You are still shown here as Contributor instead of Caollaborator.

[GitOldGrumpy]

Looks good to me.

Strange, merging ist still blocked :-/ Can you please approve these changes @GitOldGrumpy?

Have you received and accepted the Maintainer invitation E-Mail? You are still shown here as Contributor instead of Caollaborator.

Yes I had seen the email, didn't realise I had to accept! I've done that now and it approved. Know cant merge because of open conversations.