fixed error in report-code-coverage

Author: dmitriy

Makefile

@@ -138,7 +138,7 @@ phpunit:
 
 ###> php-coveralls ###
 report-code-coverage: ## update code coverage on coveralls.io. Note: COVERALLS_REPO_TOKEN should be set on CI side.
-	@make exec cmd="export COVERALLS_REPO_TOKEN=${COVERALLS_REPO_TOKEN} && php ./vendor/bin/php-coveralls -v --coverage_clover reports/clover.xml --json_path reports/coverals.json"
+	@make exec-bash cmd="export COVERALLS_REPO_TOKEN=${COVERALLS_REPO_TOKEN} && php ./vendor/bin/php-coveralls -v --coverage_clover reports/clover.xml --json_path reports/coverals.json"
 ###< php-coveralls ###
 
 ###> phpcs ###