update travis configuration

Author: chfw

.travis.yml

@@ -1,3 +1,4 @@
+sudo: false
 language: python
 notifications:
   email: false
@@ -8,12 +9,13 @@ python:
   - 2.7
   - 3.3
   - 3.4
+  - 3.5
   - pypy
 install:
   - pip install -r requirements.txt
   - pip install git+https://github.com/chfw/pyexcel-io.git
   - pip install git+https://github.com/chfw/pyexcel.git
-  - pip install -r tests/requirements.txt --use-mirrors
+  - pip install -r tests/requirements.txt
 script:
   make test
 after_success: