/bin/bash -> /usr/bin/env bash

This enables NixOS users to run the scripts in tools folder. I don't
think it will break compatibility with other distros or make any
breaking changes.

tools/build

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -e
 

tools/build-loop

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 TRAPPING=0
 trap "{ echo finishing; TRAPPING=1; }" SIGINT

tools/format

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -eo pipefail
 

tools/generate

@@ -1,3 +1,3 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 exec go run tools/generate.go $@

tools/measure

@@ -1,3 +1,3 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 exec go run tools/measure.go

tools/serve

@@ -1,3 +1,3 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 exec go run tools/serve.go

tools/test

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Sanity testing of the examples.
 

tools/upload

@@ -1,3 +1,3 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 exec go run tools/upload.go -region us-east-1 -bucket gobyexample.com