[PATCH 2 of 2] setup: bump babel version to <2.4

[Andrew Shadura]

# HG changeset patch
# User Andrew Shadura <andrew at shadura.me>
# Date 1484423997 -3600
#      Sat Jan 14 20:59:57 2017 +0100
# Node ID 4a89c7f8144cef73e46df738be45c5b2e5667224
# Parent  15b013ad9029d572633c5e915a36058ab6fa53aa
setup: bump babel version to <2.4

Babel versions up to 2.3.* provide lots of bugfixes and maintain
backward compatibility.

diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -48,7 +48,7 @@ requirements = [
     "pygments>=1.5",
     "whoosh>=2.4.0,<=2.5.7",
     "celery>=3.1,<3.2",
-    "babel>=0.9.6,<=1.3",
+    "babel>=0.9.6,<2.4",
     "python-dateutil>=1.5.0,<2.0.0",
     "markdown==2.2.1",
     "docutils>=0.8.1",