scripts/validate-commits: use direct /bin/bash interpreter Use of '#!/bin/bash' vs '#!/usr/bin/env bash' can be argued multiple ways. For example, see: https://stackoverflow.com/questions/21612980/why-is-usr-bin-env-bash-superior-to-bin-bash/21613039 It seems to be more common to use the first approach. And we don't have a specific reason to prefer the latter. Moreover, other scripts in this repo, like 'make-release' and 'whitespacecleanup.sh' use the former too.

--- a/scripts/validate-commits	Sun Oct 27 20:51:04 2019 +0100
+++ b/scripts/validate-commits	Sun Oct 27 21:01:52 2019 +0100
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/bash
 # Validate the specified commits against test suite and other checks.
 
 if [ -n "$VIRTUAL_ENV" ]; then