try to fix numpy error with Travis CI

sreeder · sreeder · commit 939df75570bd · 2016-05-11T12:14:48.000-06:00
diff --git a/requirements_tests.txt b/requirements_tests.txt
@@ -2,7 +2,7 @@
 
 pyodbc
 pymysql
-numpy
+-I numpy
 scipy
 sqlalchemy
 matplotlib
