allow ssh non-interactive login to source bashrc

[IgorTodorovskiIBM]

• Addresses Bash does not source users bashrc file when started by non-interactive ssh command #65
• This will match the Rocket bash behaviour, as well as many other platforms, include Mac.
• Brew is also adding this flag: https://github.com/Homebrew/homebrew-core/blob/8e59f8db5505f873483790c2eb3163f9d9a082f5/Formula/b/bash.rb#L100-L106

    # When built with SSH_SOURCE_BASHRC, bash will source ~/.bashrc when
    # it's non-interactively from sshd.  This allows the user to set
    # environment variables prior to running the command (e.g. PATH).  The
    # /bin/bash that ships with macOS defines this, and without it, some
    # things (e.g. git+ssh) will break if the user sets their default shell to
    # Homebrew's bash instead of /bin/bash.
    ENV.append_to_cflags "-DSSH_SOURCE_BASHRC"

• My ubuntu machine also seems to have this enabled.

New behaviour:

ssh -i~/.ssh/id_rsa_jenkins [email protected] "ls"
<sources .bashrc>
<lists my files>

Previous behaviour:

ssh -i~/.ssh/id_rsa_jenkins [email protected] "ls"
<does not SOURCE .bashrc>
<lists my files>

[MikeFultonDev]

LGTM. Please update the bash FAQ so people know...