Fixed bash shebangs to use /usr/bin/env for better compatibility

bootstrap.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 ################ parameters ################
 # directory where the script is located

simple_make.sh

@@ -1,4 +1,4 @@
-#! /bin/bash
+#!/usr/bin/env bash
 
 if which apt-get; then
     sudo apt-get install build-essential qt5-qmake qt5-default libopenal-dev libopencv-dev \

tools/buildPackages.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Config (Update me if needed !)
 VERSION_UPSTREAM="1.0"