remove py35k from CI until work on its support ramps up, test against postgresql 9.4 which is minimum required

.travis.yml

@@ -1,13 +1,12 @@
 addons:
-  postgresql: "9.5"
+  postgresql: "9.4"
 language: python
 python:
   - "2.7"
-  - "3.5"
 install:
   - pip install coveralls
 before_script:
-  - psql -c 'create database travis_ci_test;' -U postgres
+  - psql -c "create database travis_ci_test;" -U postgres
 script:
   - coverage run --source=misago setup.py test
 after_success: