build: Enables FreeBSD support.

Changed hardcoded bash shebang to env to support multiple directory
structures (required to build on FreeBSD).

PR-URL: #671

Author: Peter Jas

dnvminstall.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 _dnvmsetup_has() {
     type "$1" > /dev/null 2>&1