Update DIND

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

contrib/dind/start.sh

-#!/bin/sh
+#!/bin/bash
 
 docker rm -f faas
-docker run --name faas --privileged -p 8080:8080 -p 9090:9090 -d faas:dind
+docker run --name faas --privileged -p 8080:8080 -p 9090:9090 -d alexellis2/faas-dind:0.6.5
 
 ./test.sh
 

contrib/dind/test.sh

-#!/bin/sh
+#!/bin/bash
 
 function test_gateway {
 for i in {1..100}