allow py34 version install on modern pythons

.travis.yml

@@ -11,11 +11,20 @@ _python:
 - &python34
   name: "Python 3.4"
   python: 3.4
+- &python35
+  name: "Python 3.5"
+  python: 3.5
+- &python36
+  name: "Python 3.6"
+  python: 3.6
 - &python37
   name: "Python 3.7"
   python: 3.7
   dist: xenial
   sudo: true
+- &pypy3
+  name: "PyPy3"
+  python: pypy3.5
 
 _helpers:
 - &install_cython pip install --upgrade Cython
@@ -104,9 +113,23 @@ jobs:
 
   - stage: test
     <<: *python34
+  - stage: test
+    <<: *python35
+  - stage: test
+    <<: *python36
+  - stage: test
+    <<: *python37
+  - stage: test
+    <<: *pypy3
 
   - <<: *test_cythonized
     <<: *python34
+  - <<: *test_cythonized
+    <<: *python35
+  - <<: *test_cythonized
+    <<: *python36
+  - <<: *test_cythonized
+    <<: *python37
 
   - stage: deploy
     # This prevents job from appearing in test plan unless commit is tagged:

setup.py

@@ -234,7 +234,7 @@ def get_simple_vars_from_src(src):
     long_description=long_description,
     classifiers=classifiers,
     keywords=keywords,
-    python_requires=">=3.4,<3.5",
+    python_requires=">=3.4",
     # While setuptools cannot deal with pre-installed incompatible versions,
     # setting a lower bound is not harmful - it makes error messages cleaner. DO
     # NOT set an upper bound on setuptools, as that will lead to uninstallable

tox.ini

@@ -5,7 +5,7 @@
 
 [tox]
 minversion = 2.0
-envlist = pep8, pylint, mypy, bandit, pep257, py34, docs, py34-nocov
+envlist = pep8, pylint, mypy, bandit, pep257, py{34,35,36,37,py3}, docs, py{34,35,36,37}-nocov
 skipsdist = True
 skip_missing_interpreters = True
 
@@ -36,6 +36,27 @@ commands =
     pip install exec_helpers --no-index -f dist
     py.test -vvv {posargs:test}
 
+[testenv:py35-nocov]
+usedevelop = False
+commands =
+    python setup.py bdist_wheel
+    pip install exec_helpers --no-index -f dist
+    py.test -vvv {posargs:test}
+
+[testenv:py36-nocov]
+usedevelop = False
+commands =
+    python setup.py bdist_wheel
+    pip install exec_helpers --no-index -f dist
+    py.test -vvv {posargs:test}
+
+[testenv:py37-nocov]
+usedevelop = False
+commands =
+    python setup.py bdist_wheel
+    pip install exec_helpers --no-index -f dist
+    py.test -vvv {posargs:test}
+
 [testenv:venv]
 commands = {posargs:}