Remove the scriptz submodule and hard-commit the files.

The submodule is a leftover from when this project was intended to work
as a series of microservices. It was meant to provide common
functionality to the builds for every microservice. That's no longer the
case, and the submodule is a pain-point both in on-boarding new
developers and running the Docker build.

script/include/test_functions.inc.sh

@@ -0,0 +1,25 @@
+# test_functions.inc.sh: Functions used by the run_test script
+
+run_python_lint() {
+  local python_files="${1}"
+
+  run_command "pylint ${python_files}"
+  return $?
+}
+
+run_python_static_analysis() {
+  local python_files="${1}"
+
+  run_command "bandit -c ./.bandit_config -r ${python_files}"
+  return $?
+}
+
+run_python_unit_tests() {
+  run_command "python -m pytest -s"
+  return $?
+}
+
+run_javascript_tests() {
+  run_command "yarn test:coverage"
+  return $?
+}