Update tox and appveyor environments to use py36 by default

Author: nicoddemus

.travis.yml

@@ -20,11 +20,11 @@ env:
     - TOXENV=py27-trial
     - TOXENV=py27-numpy
     - TOXENV=py27-pluggymaster
-    - TOXENV=py35-pexpect
-    - TOXENV=py35-xdist
-    - TOXENV=py35-trial
-    - TOXENV=py35-numpy
-    - TOXENV=py35-pluggymaster
+    - TOXENV=py36-pexpect
+    - TOXENV=py36-xdist
+    - TOXENV=py36-trial
+    - TOXENV=py36-numpy
+    - TOXENV=py36-pluggymaster
     - TOXENV=py27-nobyte
     - TOXENV=doctesting
     - TOXENV=docs

appveyor.yml

@@ -22,11 +22,11 @@ environment:
   - TOXENV: "py27-trial"
   - TOXENV: "py27-numpy"
   - TOXENV: "py27-pluggymaster"
-  - TOXENV: "py35-pexpect"
-  - TOXENV: "py35-xdist"
-  - TOXENV: "py35-trial"
-  - TOXENV: "py35-numpy"
-  - TOXENV: "py35-pluggymaster"
+  - TOXENV: "py36-pexpect"
+  - TOXENV: "py36-xdist"
+  - TOXENV: "py36-trial"
+  - TOXENV: "py36-numpy"
+  - TOXENV: "py36-pluggymaster"
   - TOXENV: "py27-nobyte"
   - TOXENV: "doctesting"
   - TOXENV: "py35-freeze"