Add patch to mark admin-test as a bash script, not a POSIX sh script

debian/patches/series

@@ -4,3 +4,4 @@ Symlink-libreaddir-rand.so-into-tests-directory.patch
 tap-test-clean-up-temporary-test-directories-as-intended.patch
 In-tests-that-use-gpg-terminate-the-gpg-agent-after-testi.patch
 Load-g-i-bindings-from-builddir-during-build-time-testing.patch
+tests-admin-test.sh-this-is-a-bash-script-not-a-POSIX-sh-.patch

debian/patches/tests-admin-test.sh-this-is-a-bash-script-not-a-POSIX-sh-.patch

@@ -0,0 +1,23 @@
+From: Simon McVittie <smcv@debian.org>
+Date: Thu, 31 Mar 2016 09:48:18 +0100
+Subject: tests/admin-test.sh: this is a bash script, not a POSIX sh script
+
+The "function foo()" syntax is bash-specific, and Colin indicated in
+PR #226 that he prefers to require bash rather than trying to support
+every POSIX shell.
+
+Signed-off-by: Simon McVittie <smcv@debian.org>
+---
+ tests/admin-test.sh | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/tests/admin-test.sh b/tests/admin-test.sh
+index 3a04a69..43dcbb5 100755
+--- a/tests/admin-test.sh
++++ b/tests/admin-test.sh
+@@ -1,4 +1,4 @@
+-#!/bin/sh
++#!/bin/bash
+ # Copyright (C) 2011,2014 Colin Walters <walters@verbum.org>
+ #
+ # This library is free software; you can redistribute it and/or