display all warnings emitted during tests

Author: Changaco

tox.ini

@@ -5,7 +5,7 @@ skipsdist=True
 [testenv]
 passenv = LIBARCHIVE
 commands=
-    python -m pytest -vv --boxed --cov libarchive --cov-report term-missing {toxinidir}/tests {posargs}
+    python -m pytest -Wd -vv --boxed --cov libarchive --cov-report term-missing {toxinidir}/tests {posargs}
     flake8 {toxinidir}
 deps=
     flake8