Do not install python-jose for the flake8 check.

Rémy HUBSCHER · Rémy HUBSCHER · commit e4ac97743908 · 2017-12-20T13:39:58.000+01:00
diff --git a/tox.ini b/tox.ini
@@ -16,5 +16,6 @@ deps =
 
 [testenv:flake8]
 commands = flake8 jose
+skip_install= True
 deps =
     flake8
