use travis docker env

Author: dbu

.travis.yml

@@ -3,8 +3,11 @@ language: python
 python:
     - "2.7"
 
-before_script:
-    - sudo apt-get install enchant
+sudo: false
+
+addons:
+    apt:
+        packages: [enchant]
 
 install: "pip install -q -r requirements.txt --use-mirrors"