Fix travis

.travis.yml

@@ -5,15 +5,17 @@ env:
 
 python:
   - 3.4
+  - 3.5
+  - 3.6
 
-services:
-  - postgresql
+addons:
+  postgresql: "9.5"
+  apt:
+    packages:
+      - postgresql-9.5-postgis-2.3
 
 before_script:
-  - flake8 tests ogn
-  - sudo apt-get autoremove postgis*
-  - sudo apt-get autoremove postgresql*
-  - sudo apt-get install postgresql-9.3-postgis-2.1
+  - flake8 tests ogn_test
   - psql -c 'CREATE DATABASE ogn_test;' -U postgres
   - psql -c 'CREATE EXTENSION postgis;' -U postgres -d ogn_test