Add mypy and add typechecking step to script/test

Only check atst/domain/csp/cloud.py for now

script/include/run_test

@@ -35,6 +35,9 @@ if [ "${RUN_PYTHON_TESTS}" = "true" ]; then
   output_divider "Perform static analysis on Python files"
   run_python_static_analysis "${PYTHON_FILES}"
   ((python_test_status+=$?))
+  output_divider "Perform type checking on Python files"
+  run_python_typecheck
+  ((python_test_status+=$?))
   output_divider "Run Python unit test suite"
   run_python_unit_tests "${PYTHON_FILES}"
   ((python_test_status+=$?))

script/include/test_functions.inc.sh

@@ -7,6 +7,11 @@ run_python_lint() {
   return $?
 }
 
+run_python_typecheck() {
+  run_command "mypy --ignore-missing-imports --follow-imports=skip atst/domain/csp/cloud.py"
+  return $?
+}
+
 run_python_static_analysis() {
   local python_files="${1}"