Whitespace not handled correctly in OS driver environment variables

This line and the one after it are the culprits https://github.com/CSCfi/pebbles/blob/master/pebbles/drivers/provisioning/openshift_driver.py#L342

Passing an environment variable like COMMAND="jupyter lab" will split at whitespace and make blueprint unstartable.

Start at pebbles/drivers/provisioning/openshift_driver.py around line 342 and inspect the two referenced lines that process environment variables. Reproduce the issue with an environment value such as COMMAND="jupyter lab" and verify that the blueprint starts successfully without splitting the value at whitespace.

Written by the indexing model from the issue text.