remove Travis CI workaround from Makefile

Makefile

@@ -19,11 +19,10 @@ cov cover coverage: pre-commit
 	python -Wd -m pytest -s -vv --cov-report term --cov-report html --cov aiobotocore ./tests
 	@echo "open file://`pwd`/htmlcov/index.html"
 
-# BOTO_CONFIG solves https://github.com/travis-ci/travis-ci/issues/7940
 mototest:
 	docker pull alpine
 	docker pull lambci/lambda:python3.8
-	BOTO_CONFIG=/dev/null python -Wd -X tracemalloc=5 -X faulthandler -m pytest -vv -m moto -n auto --cov-report term --cov-report html --cov-report xml --cov=aiobotocore --cov=tests --log-cli-level=DEBUG $(FLAGS) aiobotocore tests
+	python -Wd -X tracemalloc=5 -X faulthandler -m pytest -vv -m moto -n auto --cov-report term --cov-report html --cov-report xml --cov=aiobotocore --cov=tests --log-cli-level=DEBUG $(FLAGS) aiobotocore tests
 	@echo "open file://`pwd`/htmlcov/index.html"
 
 clean: