Use a notation so the tests are run with the specified python version…

… locally.

tox.ini

@@ -2,27 +2,24 @@
 envlist =
     basetest,
     coverage-clean,
-    py{
-      27
-      33
-      34
-      35
-      36
-      py
-      py2
-      py3
-    },
+    py27,
+    py33,
+    py34,
+    py35,
+    py36,
+    pypy,
+    pypy2,
+    pypy3,
     coverage-report,
     isort,
     #flake8,
 skip_missing_interpreters = True
 
 [testenv]
-basepython = python
 install_command = pip install --egg {opts} {packages}
 usedevelop = True
 commands =
-    py.test --tb=long --cov=src --cov-report=xml {posargs}
+    py.test --cov=src --cov-report=xml {posargs}
     #    py.test -x --pdb --tb=long --cov=src --cov-report=xml {posargs}
 setenv =
   COVERAGE_FILE=.coverage.{envname}