Switching MYSQL travis to 5.7

Author: moufmouf

phpunit.xml.dist

@@ -19,9 +19,9 @@
 
     <php>
         <!-- "Real" test database -->
-        <var name="db_host" value="127.0.0.1" />
+        <var name="db_host" value="localhost" />
         <var name="db_username" value="root" />
-        <var name="db_password" value="root" />
+        <var name="db_password" value="" />
         <var name="db_name" value="tdbm_graphql_testcase" />
         <var name="db_port" value="3306"/>
         <var name="db_driver" value="pdo_mysql"/>