CI: Install and use Python 3.3.7

Author: effigies

.circleci/config.yml

@@ -371,7 +371,8 @@ jobs:
       - run:
           name: Check python_requires prevents installation on Python 3.3
           command: |
-            pyenv local 3.3.6
+            pyenv install 3.3.7
+            pyenv local 3.3.7
             FAIL=false
             pip install dist/nipype-*-py2.py3-none-any.whl || FAIL=true
             $FAIL