Update travis

Author: methane

.travis.yml

@@ -1,19 +1,18 @@
 sudo: false
 language: python
-python: "3.4"
-env:
-    - TOX_ENV=py27
-    - TOX_ENV=py33
-    - TOX_ENV=py34
-    - TOX_ENV=pypy
-    - TOX_ENV=pypy3
+python:
+  - "3.6"
+  - "3.5"
+  - "3.4"
+  - "2.7"
+  - "pypy"
 
 install:
-    - pip install -U tox
+    - pip install -U tornado
 
 before_script:
     - "mysql -e 'create database test_pymysql  DEFAULT CHARACTER SET utf8 DEFAULT COLLATE utf8_general_ci;'"
     - "mysql -e 'create database test_pymysql2 DEFAULT CHARACTER SET utf8 DEFAULT COLLATE utf8_general_ci;'"
     - cp .travis.databases.json tornado_mysql/tests/databases.json
 
-script: tox -e $TOX_ENV
+script: ./runtests.py