Fix certificate directory creation

When calling ./stack.sh twice, octavia devstack plugin fails because
local certificate directory already exists.

This commit deletes the directory each time a certificate creation
script is called and when the user cleans up his devstack's
installation.

Change-Id: I21dfffa9b30274fa0fa9f365a88222b8f4c89e29

bin/create_dual_intermediate_CA.sh

@@ -27,6 +27,7 @@ set -x -e
 
 CA_PATH=dual_ca
 
+rm -rf $CA_PATH
 mkdir $CA_PATH
 chmod 700 $CA_PATH
 cd $CA_PATH

bin/create_single_CA_intermediate_CA.sh

@@ -27,6 +27,7 @@ set -x -e
 
 CA_PATH=single_ca
 
+rm -rf $CA_PATH
 mkdir $CA_PATH
 chmod 700 $CA_PATH
 cd $CA_PATH

devstack/plugin.sh

@@ -590,6 +590,9 @@ function octavia_cleanup {
         _cleanup_octavia_apache_wsgi
     fi
 
+    sudo rm -rf $OCTAVIA_DIR/bin/dual_ca
+    sudo rm -rf $OCTAVIA_DIR/bin/single_ca
+
     sudo rm -rf $NOVA_STATE_PATH $NOVA_AUTH_CACHE_DIR
 
     sudo rm -f /etc/rsyslog.d/10-octavia-log-offloading.conf