Options to relocate temporaryDirectory

[xmlking]

I was trying Hasura-auth software which is using this lib.
When I run this in docker container with non-root user, it keep failing due to permissions.
ASK : please provide options to specify the temp location either via API or via environment variables

[tonimelisma]

Hey @xmlking - I'm more than happy to review a PR. Please check the contributing documentation, and write a unit test.

[xmlking]

I found a solution to support non-root runner use case:
by setting environment variable TMPDIR=/some_temp_root we can control base directory for ioutil.TempDir()