test: io.StringIO expects unicode object as argument.

caucase/test.py

@@ -1655,37 +1655,37 @@ class CaucaseTest(unittest.TestCase):
       'PATH_INFO': '/cau/crt/renew',
       'REQUEST_METHOD': 'PUT',
       'CONTENT_TYPE': 'application/json',
-      'wsgi.input': StringIO('{'),
+      'wsgi.input': StringIO(u'{'),
     })[0], 400)
     self.assertEqual(request({
       'PATH_INFO': '/cau/crt/revoke',
       'REQUEST_METHOD': 'PUT',
       'CONTENT_TYPE': 'application/json',
-      'wsgi.input': StringIO('{"digest": null}'),
+      'wsgi.input': StringIO(u'{"digest": null}'),
     })[0], UNAUTHORISED_STATUS)
     self.assertEqual(request({
       'PATH_INFO': '/cau/crt/revoke',
       'REQUEST_METHOD': 'PUT',
       'CONTENT_TYPE': 'application/json',
-      'wsgi.input': StringIO('{"digest":"sha256","payload":""}'),
+      'wsgi.input': StringIO(u'{"digest":"sha256","payload":""}'),
     })[0], 400)
     self.assertEqual(request({
       'PATH_INFO': '/cau/crt/a',
       'REQUEST_METHOD': 'PUT',
       'CONTENT_TYPE': 'text/plain',
-      'wsgi.input': StringIO(''),
+      'wsgi.input': StringIO(u''),
     })[0], 400)
     self.assertEqual(request({
       'PATH_INFO': '/cau/crt/123',
       'REQUEST_METHOD': 'PUT',
       'CONTENT_TYPE': 'text/plain',
-      'wsgi.input': StringIO(''),
+      'wsgi.input': StringIO(u''),
     })[0], UNAUTHORISED_STATUS)
     self.assertEqual(request({
       'PATH_INFO': '/cau/crt/123',
       'REQUEST_METHOD': 'PUT',
       'CONTENT_TYPE': 'text/plain',
-      'wsgi.input': StringIO('foo'),
+      'wsgi.input': StringIO(u'foo'),
     })[0], 400)
     self.assertEqual(request({
       'PATH_INFO': '/cau/crt/123',