Fixed issues running tests on Python 2.6 and 3.3

Author: fuzeman

.travis.yml

@@ -12,7 +12,7 @@ python:
 install:
   - travis_retry pip install coveralls
   - travis_retry pip install tox-travis
-  - if [[ $TRAVIS_PYTHON_VERSION != 'pypy'* ]]; then travis_retry pip install pyOpenSSL>=16.2.0; fi
+  - if [[ $TRAVIS_PYTHON_VERSION != 'pypy'* ]]; then travis_retry pip install cryptography~=1.3.4 pyOpenSSL~=16.2.0; fi
 script:
   tox
 after_success:

tox.ini

@@ -16,6 +16,16 @@ deps =
 commands =
   coverage erase
 
+[testenv:py26]
+deps =
+  pytest==3.2.4
+  pytest-cov
+
+[testenv:py33]
+deps =
+  pytest==3.2.4
+  pytest-cov
+
 [testenv:flake8]
 basepython = python
 skip_install = true