Fix shebangs in new scripts after rebasing

terraform/aws/scripts/install.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -e
 
 echo "Installing dependencies..."

terraform/aws/scripts/ip_tables.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -e
 
 sudo iptables -I INPUT -s 0/0 -p tcp --dport 8300 -j ACCEPT

terraform/aws/scripts/service.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -e
 
 echo "Starting Consul..."