Let env find bash

[Thefrank]

Fixes source building under FreeBSD where a symlink has not been made for bash

Context

/bin/bash is standard under OSes that ship with bash installed by default. FreeBSD does not have bash as a default shell.

Changes Made

For portability /usr/bin/env bash is used on the shebang line. This also bring it inline with other dotnet repos.

Testing

none needed?

Notes

env is standard at this point. I have been unable to find a non-historic UNIX-like system that places env in a location exclusively that is not /usr/bin/

[rainersigwald]

Thanks!

[Forgind]

Thanks @Thefrank!