Write upper-constraints to working-dir

Change-Id: I09e6d10385479ecb23af6391c09b67d42dead201
diff --git a/turbo_hipster/task_plugins/real_db_upgrade/nova_mysql_migrations.sh b/turbo_hipster/task_plugins/real_db_upgrade/nova_mysql_migrations.sh
index cd8cd38..408d7f4 100755
--- a/turbo_hipster/task_plugins/real_db_upgrade/nova_mysql_migrations.sh
+++ b/turbo_hipster/task_plugins/real_db_upgrade/nova_mysql_migrations.sh
@@ -48,9 +48,9 @@
     requires="requirements.txt"
   fi
 
-  wget http://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt?h=$1
+  wget http://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt?h=$1 -O $WORKING_DIR_PATH/upper-constraints.txt
   echo "Install pip requirements from $requires"
-  pip install -c upper-constraints.txt -r $requires
+  pip install -c $WORKING_DIR_PATH/upper-constraints.txt -r $requires
 
   # Workaround for old python version on ubuntu-precise
   ubuntu_version=$( lsb_release -r | awk '{ print $2 }' | sed 's/[.]//' )