Run py34 tests in tox.

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 downloadcache = {toxworkdir}/cache/
-envlist = py27, pypy, py27-noext, pypy-noext
+envlist = py26, py27, pypy, py27-noext, pypy-noext, py34, py34-noext
 
 [testenv]
 deps =
@@ -10,17 +10,11 @@ commands = make check
 recreate = True
 whitelist_externals = make
 
-[testenv:py24]
-setenv =
-    PIP_INSECURE=1
-
-
-[testenv:py25]
-setenv =
-    PIP_INSECURE=1
-
 [testenv:py27-noext]
 commands = make check-noextensions
 
 [testenv:pypy-noext]
 commands = make check-noextensions
+
+[testenv:py34-noext]
+commands = make check-noextensions