Migrated several JobTransforms related modules to Python3 using futurize
Short term the code should work in both versions of Python, the futurize tool was used for basic migration. This adds some overhead with additional libraries which should be removed once a full transition to Python 3 is done. Additionally various error prone cases where the "is" operator has been used were changed and now use the "==" operator instead.
Most of the modules were properly tested with the existing unit tests from PyJobTransforms. Since the scope of the changes is quite big a few modules might have been missed there. Changes were mostly made with basic the basic futurize migration strategy, autopep8 for code style, followed by adding manual fixes.
I consider the work for those modules done, additional test scenarios could be discussed before fully merging the changes into master.
EDIT: Proper testing would involve getting everything to run solely on Python 3, which I couldn't make work yet on lxplus.