tox: use psycopg2-binary (#622)

Author: blueyed

tox.ini

@@ -24,7 +24,7 @@ deps =
     mysql_myisam: mysql-python==1.2.5
     mysql_innodb: mysql-python==1.2.5
 
-    postgres: psycopg2
+    postgres: psycopg2-binary
 setenv =
     PYTHONPATH = {toxinidir}:{env:PYTHONPATH:}