travis: move osx test to the top

OSX is the slow one, so it should start straight away.

.travis.yml

@@ -20,6 +20,12 @@ matrix:
   include:
     - python: 3.5
       env: TOXENV=lint
+    - language: generic
+      os: osx
+      osx_image: xcode7.1
+      git:
+        depth: 9999999
+      env: TOXENV=py27
     - python: 3.5
       env: TOXENV=py35
     - python: 3.5
@@ -28,12 +34,6 @@ matrix:
       env: TOXENV=py27
     - python: 2.7
       env: TOXENV=py27 NO_ALPN=1
-    - language: generic
-      os: osx
-      osx_image: xcode7.1
-      git:
-        depth: 9999999
-      env: TOXENV=py27
     - python: 3.5
       env: TOXENV=docs
   allow_failures: