Drop EOL Python 2.6 & 3.3 from tox.ini (#470)
Drop EOL Python 2.6 & 3.3 from tox.ini (#470)

Python 2.6 support was removed in
42ef7df6a886596834c626b3cf0a4f9a6459f9f3, version 1.1.0.

Python 3.3 support was removed in
1612d7e76076242f496de5bac9045ca6233d4424, version 1.2.0.
lmctv/pynacl,reaperhulk/pynacl,lmctv/pynacl,pyca/pynacl,reaperhulk/pynacl,reaperhulk/pynacl,lmctv/pynacl,pyca/pynacl,pyca/pynacl,pyca/pynacl,reaperhulk/pynacl,reaperhulk/pynacl,lmctv/pynacl,pyca/pynacl,lmctv/pynacl