[Travis] Show logs for pip install dev.txt

tox.ini

@@ -17,7 +17,7 @@ deps=
 sitepackages = False
 recreate = False
 commands = {toxinidir}/extra/release/removepyc.sh {toxinidir}
-           pip install -q -U -r{toxinidir}/requirements/dev.txt
+           pip install -U -r{toxinidir}/requirements/dev.txt
            nosetests -xsv --with-coverage \
                 --cover-inclusive --cover-min-percentage=94 --cover-erase []