Build farm failing for swri_cli_tools

[rjb0026]

ROS build farm jobs for melodic are consistently failing for the swri_cli_tools package during the "build binarydeb" stage. The following error during building appears to be the source of the build failure:

03:03:55 Traceback (most recent call last):
03:03:56 File "/opt/ros/melodic/share/catkin/cmake/interrogate_setup_dot_py.py", line 255, in
03:03:56 main()
03:03:56 File "/opt/ros/melodic/share/catkin/cmake/interrogate_setup_dot_py.py", line 248, in main
03:03:56 runpy.run_path(args.setupfile_path)
03:03:56 File "/usr/lib/python2.7/runpy.py", line 252, in run_path
03:03:56 return _run_module_code(code, init_globals, run_name, path_name)
03:03:56 File "/usr/lib/python2.7/runpy.py", line 82, in _run_module_code
03:03:56 mod_name, mod_fname, mod_loader, pkg_name)
03:03:56 File "/usr/lib/python2.7/runpy.py", line 72, in _run_code
03:03:56 exec code in run_globals
03:03:56 File "/tmp/binarydeb/ros-melodic-swri-cli-tools-2.15.2/setup.py", line 1, in
03:03:56 from setuptools import setup
03:03:56 ImportError: No module named setuptools

The distutils.core package should be used to import the setup function instead.

[rjb0026]

Added fallback to distutils.core.setup in #687