Fail if any warning is emitted and not handled.
Note that due to an old version of virtualenv used to bootstrap travis, we need to ignore warnings from the fake distutils.
include ../makefiles/Makefile.inc
+# distutils warnings are caused by an old version of virtualenv in travis
+export PYTHONWARNINGS = error,ignore::DeprecationWarning:distutils
+
REGRESSIONS := $(shell ls test_cases/)
.PHONY: $(REGRESSIONS)
