updated to supported versions

Author: auvipy

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = 2.6,2.7,pypy,3.3,3.4,3.5,pypy3,flake8,flakeplus
+envlist = 2.7,pypy,3.7,3.6,3.5,pypy3,flake8,flakeplus
 
 [testenv]
 deps=
@@ -12,10 +12,10 @@ commands = {toxinidir}/extra/release/removepyc.sh {toxinidir}
                 --cover-inclusive --cover-erase []
 
 basepython =
-    2.6: python2.6
+    
     2.7: python2.7
-    3.3: python3.3
-    3.4: python3.4
+    3.7: python3.7
+    3.6: python3.6
     3.5: python3.5
     pypy: pypy
     pypy3: pypy3