Merge pull request #87 from rkdarst/min_jupyterhub_0.8.1

.travis.yml: update Jupyterhub and Python vers tested

Author: mbmilligan

.travis.yml

@@ -5,26 +5,22 @@ python:
     - 3.6
     - 3.5
     - 3.4
-    - 3.3
 env:
-    - JHUB_VER=0.5.0
-    - JHUB_VER=0.6.1
     - JHUB_VER=0.7.2
     - JHUB_VER=0.8.1
     - JHUB_VER=0.9.0b2
 matrix:
     include:
-    - python: 3.6
-      env: JHUB_VER=master
+     - python: 3.7-dev
+       env: JHUB_VER=0.9.0b2
+     - python: 3.6
+       env: JHUB_VER=master
     exclude:
-    - python: 3.3
-      env: JHUB_VER=0.8.1
-    - python: 3.3
-      env: JHUB_VER=0.9.0b2
-    - python: 3.4
-      env: JHUB_VER=0.9.0b2
+     - python: 3.4
+       env: JHUB_VER=0.9.0b2
     allow_failures:
       - env: JHUB_VER=master
+      - python: 3.7-dev
 
 before_install:
     - npm install -g configurable-http-proxy