fix: freebsd build support (#1659)

- Avoid hard-coding the path for bash - this typically is installed as
  /usr/local/bin/bash

- Allow for the fact that FreeBSD's rlimit uses signed integers

Almost all of the test suite passes with three test failures that I
haven't tried to debug yet.

Signed-off-by: Doug Rabson <dfr@rabson.org>

test/scripts/fuzzAll.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -e
 
@@ -15,4 +15,4 @@ do
         parentDir=$(dirname $file)
         go test $parentDir -run=$func -fuzz=$func$ -fuzztime=${fuzzTime}s -tags sync,metrics,search,scrub,containers_image_openpgp | grep -oP -x '^(?:(?!\blevel\b).)*$'
     done
-done
+done

test/scripts/gen_certs.sh

@@ -1,4 +1,6 @@
-#!/bin/bash -xe
+#!/usr/bin/env bash
+
+set -xe
 
 openssl req \
     -newkey rsa:2048 \

test/scripts/gen_nameless_certs.sh

@@ -1,4 +1,6 @@
-#!/bin/bash -xe
+#!/usr/bin/env bash
+
+set -xe
 
 openssl req \
     -newkey rsa:2048 \