Tox: Removes 2.7.6 target that does not work

tox.ini

@@ -6,7 +6,7 @@ deps=
     -r{toxinidir}/requirements/default.txt
     -r{toxinidir}/requirements/test.txt
 
-    2.7,2.7.6: -r{toxinidir}/requirements/test-ci-default.txt
+    2.7: -r{toxinidir}/requirements/test-ci-default.txt
     3.4,3.5: -r{toxinidir}/requirements/test-ci-default.txt
     pypy,pypy3: -r{toxinidir}/requirements/test-ci-base.txt
 
@@ -20,7 +20,6 @@ commands = pip install -U -r{toxinidir}/requirements/dev.txt
 
 basepython =
     2.7,flake8,flakeplus,apicheck,linkcheck,configcheck: python2.7
-    2.7.6: python2.7.6
     3.4: python3.4
     3.5: python3.5
     pypy: pypy