add typing for python < 3.5

setup.py

@@ -1,5 +1,6 @@
 import os
 
+import sys
 from setuptools import setup, find_packages
 
 here = os.path.abspath(os.path.dirname(__file__))
@@ -31,6 +32,11 @@ tests_require = [
     'nose',
 ]
 
+# Python version adaptations
+if sys.version_info < (3, 5):
+    requires.append('typing')
+
+
 setup(
     name='tracim',
     version='0.0',