use env bash shebangs for portability (#11)

Signed-off-by: Jakub Sokołowski <jakub@status.im>

README.md

@@ -334,7 +334,7 @@ necessary for using this build system. It's being sourced by a script with the
 same name in the superproject's top directory:
 
 ```bash
-#!/bin/bash
+#!/usr/bin/env bash
 
 # We use ${BASH_SOURCE[0]} instead of $0 to allow sourcing this file
 # and we fall back to a Zsh-specific special var to also support Zsh.

scripts/add_submodule.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Copyright (c) 2018-2020 Status Research & Development GmbH. Licensed under
 # either of:

scripts/build_nim.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # used in Travis CI and AppVeyor scripts
 
 # Copyright (c) 2018-2020 Status Research & Development GmbH. Licensed under

scripts/build_p2pd.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Copyright (c) 2018-2020 Status Research & Development GmbH. Licensed under
 # either of:

scripts/build_rocksdb.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # used in Travis CI scripts
 
 # Copyright (c) 2018-2020 Status Research & Development GmbH. Licensed under

scripts/create_nimble_link.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Copyright (c) 2018-2019 Status Research & Development GmbH. Licensed under
 # either of:

scripts/env.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Copyright (c) 2018-2019 Status Research & Development GmbH. Licensed under
 # either of:

scripts/git_show_deps.sh

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

scripts/nimble.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Copyright (c) 2018-2019 Status Research & Development GmbH. Licensed under
 # either of: