Big clean up of release.py script

[j-rivero]

A big first clean up in the ancient release.py script. Some major changes that I believe probably noone was using nowadays:

• Remove --no-ignition-auto option
• Remove --upstream option
• Remove i386 from release.py (Bionic is the last Ubuntu and we are probably not interested into Debian/i386)
• For create_tarball_name remove the option of package_alias (broken)
• Remove sanity_check_gazebo_versions (outdated)

Formatting/Linting fixes:

• Remove unused variables
• 2 lines after methods
• Fix spacing and blank lines
• Use byte stream for empty return type in check_call
• Change method not to end up in exit

The changes are easier to navigate commit-by-commit, the commit description should be good to understand each of them.