Use pytest instead of py.test per upstream recommendation, #dropthedot

http://blog.pytest.org/2016/whats-new-in-pytest-30/
https://twitter.com/hashtag/dropthedot

.travis.yml

@@ -30,7 +30,7 @@ before_script:
 
 script:
   - pip install -e .
-  - py.test --cov ./MySQLdb
+  - pytest --cov ./MySQLdb
 
 after_succes:
   - codecov

tests/test_cursor.py

@@ -1,4 +1,4 @@
-import py.test
+import pytest
 import MySQLdb.cursors
 from configdb import connection_factory