[REGRESSION] more fixes for stability and reliability (- WIP #46 & #50 …

…-)

### ChangeLog:

Changes in file Makefile:
 test-tox: cleanup

Changes in file tests/check_codecov_regression:
 if [[ (${EXIT_CODE} -eq 0) ]] ; then

Makefile

@@ -166,7 +166,7 @@ test-reports:
 	$(QUIET)$(ECHO) "$@: Done."
 
 test-pytest: cleanup must_have_pytest test-reports
-	$(QUIET)$(PYTHON) -B -m pytest --cache-clear --doctest-glob=multicast/*.py,tests/*.py --doctest-modules --cov=. --cov-append --cov-report=xml --junitxml=test-reports/junit.xml -v --rootdir=. || DO_FAIL="exit 2" ;
+	$(QUIET)$(PYTHON) -B -m pytest --cache-clear --doctest-glob=multicast/*.py,tests/*.py --doctest-modules --cov=  --cov-append --cov-report=xml --junitxml=test-reports/junit.xml -v --rootdir=. || DO_FAIL="exit 2" ;
 	$(QUIET)$(DO_FAIL) ;
 	$(QUIET)$(ECHO) "$@: Done."
 

tests/check_codecov_regression

@@ -136,6 +136,7 @@ if [[ (${EXIT_CODE} -eq 0) ]] ; then
 	fi
 	if [[ (${EXIT_CODE} -eq 0) ]] ; then
 		make -C "${_TEST_ROOT_DIR}" -f "${_TEST_ROOT_DIR}/Makefile" test-pytest 1>/dev/null 2>&1 || EXIT_CODE=3 ;
+		wait ;
 		if [[ (${EXIT_CODE} -eq 0) ]] ; then
 			test -r "${_TEST_ROOT_DIR}/.coverage" 1>/dev/null 2>&1 || test -r "${_TEST_ROOT_DIR}/.coverage.*" 1>/dev/null 2>&1 || test -r "${_TEST_ROOT_DIR}/coverage.*" 1>/dev/null 2>&1 || EXIT_CODE=3 ;
 		fi