Remove setup_functional_test.sh

That is just calling s2aio.sh for our functional gate but
just calling it at the playbook is easier so let's remove
the unnecessary bash shell.

Change-Id: Ic2820c681295e2e1b68bbf91d6fa70de266cdedc

playbooks/storlets-functional/pre.yaml

@@ -4,6 +4,6 @@
         cmd: |
           set -e
           set -x
-          tests/setup_functional_test.sh
+          ./s2aio.sh install
         executable: /bin/bash
         chdir: 'src/{{ zuul.project.canonical_name }}'

tests/setup_functional_test.sh

@@ -1,2 +0,0 @@
-#!/bin/bash
-./s2aio.sh install