Revert "jobs: Fixing environment required to run catkin test targets on pre-indigo catkin"

[meyerj]

This pull requests suggest to revert #265 ([PR196+] jobs: Fixing environment required to run catkin test targets on pre-indigo catkin), which is supposed to be obsolete. According to the description and inline comments it was only required for ROS Hydro and earlier.

If complete removal is too disruptive, I suggest to only install the env-hook in ROS Hydro and earlier (not sure what would be a reliable way to detect this, before any workspace is sourced).

Rationale:

• The CATKIN_TEST_RESULTS_DIR is not used anymore by catkin since remove CATKIN_TEST_RESULTS_DIR environment variable ros/catkin#728. Not sure about ROS_TEST_RESULTS_DIR, I did not check.
• The additional env-hook get installed unconditionally and "pollutes" the devel- and install-spaces, although normally it should not do any harm.
• In some cases it does harm, e.g. when building Debians using catkin_tools. catkin itself has flags like CATKIN_BUILD_BINARY_PACKAGE that prevents installation of common files in a shared install-space. 06-ctr-nuke.sh did not respect this and required manual removal from the staged DESTDIR to avoid that the file is added to multiple binary packages (see also related issue DESTDIR broken on master #280).

[mikepurvis]

This looks reasonable; there's no reason to be supporting pre-Indigo distros at this point, heck the master branch doesn't even work with Python 2 any more. :)