BUILD: Make curl verbose on errors

Makefile

@@ -45,7 +45,7 @@ install:
 #
 
 isort:
-	curl -sfLo .isort.cfg $(LINTER_CONFIGS)/isort.cfg
+	curl -sSfLo .isort.cfg $(LINTER_CONFIGS)/isort.cfg
 	isort $(SOURCE_DIRS)
 
 #
@@ -53,19 +53,19 @@ isort:
 #
 
 test-isort:
-	curl -sfLo .isort.cfg $(LINTER_CONFIGS)/isort.cfg
+	curl -sSfLo .isort.cfg $(LINTER_CONFIGS)/isort.cfg
 	isort -c --diff $(SOURCE_DIRS)
 
 test-pycodestyle:
-	curl -sfLo tox.ini $(LINTER_CONFIGS)/tox.ini
+	curl -sSfLo tox.ini $(LINTER_CONFIGS)/tox.ini
 	pycodestyle $(SOURCE_DIRS)
 
 test-pylint:
-	curl -sfLo .pylintrc $(LINTER_CONFIGS)/pylintrc
+	curl -sSfLo .pylintrc $(LINTER_CONFIGS)/pylintrc
 	pylint $(SOURCE_DIRS)
 
 test-unittest:
-	curl -so .coveragerc $(LINTER_CONFIGS)/coveragerc
+	curl -sSfLo .coveragerc $(LINTER_CONFIGS)/coveragerc
 	coverage run $(which python) -m unittest
 
 test-coverage: