Fix ImportError due to lack of typing on python3.4

Fix #4

.travis.yml

@@ -4,4 +4,6 @@ python:
 - 3.5
 - 3.6
 install: pip install tox-travis
-script: tox
+script:
+- tox
+- tox -e mypy

docs/changes.rst

@@ -6,6 +6,9 @@ Version 0.5.4
 
 To be released.
 
+- Fixed :exc:`ImportError` on Python 3.4 due to lack of :mod:`typing` module.
+  [:issue:`4`]
+
 
 Version 0.5.3
 '''''''''''''

setup.py

@@ -47,6 +47,7 @@ def readme():
     packages=find_packages(exclude=['docs', 'tests']),
     python_requires='>=3.4.0',
     install_requires=['Babel >= 2.0'],
+    extras_require={':python_version<"3.5"': ['typing']},
     keywords='wikidata ontology',
     classifiers=[
         'Development Status :: 4 - Beta',

tox.ini

@@ -1,16 +1,21 @@
 [tox]
-envlist = py34, py35, py36
+envlist = py34, py35, py36, mypy
 
 [testenv]
 deps =
     flake8 >= 3.3.0
     flake8-import-order-spoqa
-    mypy >= 0.511
     pytest >= 3.0.7, < 3.1.0
-    pytest-capturelog >= 0.7, < 1.0
+    pytest-catchlog >= 1.2.2, < 1.3.0
     pytest-flake8 >= 0.8.1, < 0.9.0
 commands =
     pytest {posargs:}
+
+[testenv:mypy]
+basepython = python3
+deps =
+    mypy >= 0.521
+commands =
     mypy -p wikidata
     mypy -p tests