Support http-basic-auth via basicAuth setting

[staabm]

use settings.basicAuth.username and settings.basicAuth.password to
configure basic authentication.

[staabm]

see #36 (comment)

[scottgonzalez]

Please either break before the operators:

        basic_auth: settings.basicAuth
            ? {
                user: settings.basicAuth.username,
                pass: settings.basicAuth.password
            }
            : null

Or invert the conditional:

        basic_auth: !settings.basicAuth ? null : {
            user: settings.basicAuth.username,
            pass: settings.basicAuth.password
        }

And drop the trailing comma.

[scottgonzalez]

Thanks, this still needs docs.

[staabm]

@scottgonzalez documented the new options and adjusted CS per review

[scottgonzalez]

Released in v1.3.0.