This feature is just an extension of an existent feature.
Today the only way to send environment variables to SGE via bob.bio.base is setting the optional argument --environment.
This MR allows us to set that via configuration files by adding env=MY_VAR=VALUE.
Before any complains, I can't come up with test case for that one. This is injected directly in the Namespace object (argparse) AND this object is not visible when we I call verify.main().