support testing/linting module_utils code

This does not directly affect network because network has its own
solution for dealing with testing/linting module_utils code, but
it gets network to feature/code parity with the template and
other repos.

Defines a shell function in utils.sh - lsr_setup_module_utils -
that allows configuring a tox venv installed ansible to have
the repo module_utils code in the default pythonpath for the
venv, which allows testing and linting the module_utils code
without having to otherwise munge or mock the pythonpath.

Projects needing this functionality can set in `.travis/config.sh`
the variable `RUN_PYTEST_SETUP_MODULE_UTILS` to setup
module_utils/ for pytest, and `RUN_PYLINT_SETUP_MODULE_UTILS`
to setup module_utils/ for pylint.

tests/setup_module_utils.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+# SPDX-License-Identifier: MIT
+
+set -euo pipefail
+
+if [ -n "${DEBUG:-}" ] ; then
+    set -x
+fi
+
+if [ ! -d "${1:-}" ] ; then
+    echo Either ansible is not installed, or there is no ansible/module_utils
+    echo in $1 - Skipping
+    exit 0
+fi
+
+if [ ! -d "${2:-}" ] ; then
+    echo Role has no module_utils - Skipping
+    exit 0
+fi
+
+# we need absolute path for $2
+absmoddir=$( readlink -f "$2" )
+
+# clean up old links to module_utils
+for item in "$1"/* ; do
+    if lnitem=$( readlink "$item" ) && test -n "$lnitem" ; then
+        case "$lnitem" in
+            *"${2}"*) rm -f "$item" ;;
+        esac
+    fi
+done
+
+# add new links to module_utils
+for item in "$absmoddir"/* ; do
+    case "$item" in
+        *__pycache__) continue;;
+        *.pyc) continue;;
+    esac
+    bnitem=$( basename "$item" )
+    ln -s "$item" "$1/$bnitem"
+done