Prepare for typing.py

Author: asvetlov

requirements-dev.txt

@@ -5,3 +5,4 @@ coverage
 flake8
 pytest
 pytest-cov
+mypy-lang

setup.py

@@ -6,6 +6,8 @@
 
 from setuptools.command.test import test as TestCommand
 
+PY_35 = sys.version_info >= (3, 5)
+
 
 class PyTest(TestCommand):
     user_options = [('pytest-args=', 'a', "Arguments to pass to py.test")]
@@ -43,6 +45,10 @@ def read(f):
 extras_require = {}
 
 
+if not PY_35:
+    install_requires.append('typing')
+
+
 setup(
     name='janus',
     version=version,