add 3.7, sort in descending order

Author: willmcgugan

.travis.yml

@@ -6,18 +6,23 @@ matrix:
     - python: "2.7"
       env:
         - SETUPTOOLS=setuptools PIP=pip
-    - python: "3.3"
+    - python: "3.7"
       env:
-        - SETUPTOOLS=setuptools~=39.2 PIP="pip<=18.0"
-    - python: "3.4"
+        - SETUPTOOLS=setuptools PIP=pip
+      dist: xenial
+      sudo: true
+    - python: "3.6"
       env:
         - SETUPTOOLS=setuptools PIP=pip
     - python: "3.5"
       env:
         - SETUPTOOLS=setuptools PIP=pip
-    - python: "3.6"
+    - python: "3.4"
       env:
         - SETUPTOOLS=setuptools PIP=pip
+    - python: "3.3"
+      env:
+        - SETUPTOOLS=setuptools~=39.2 PIP="pip<=18.0"
 
 before_install:
   - pip install $SETUPTOOLS $PIP -U