build-release: Fix build failing due to missing .coveralls.yml
build-release: Fix build failing due to missing .coveralls.yml

.coveralls.yml has been superceded by codecov.yml. Update the release
build script to delete the new file.

dnmvisser/simplesamlphp,ghalse/simplesamlphp,ghalse/simplesamlphp,simplesamlphp/simplesamlphp,dnmvisser/simplesamlphp,dnmvisser/simplesamlphp,simplesamlphp/simplesamlphp,simplesamlphp/simplesamlphp,ghalse/simplesamlphp,ghalse/simplesamlphp,simplesamlphp/simplesamlphp,dnmvisser/simplesamlphp