Allow auth on mo_url

[smn]

Auth can either be basic auth:

mo_url: 'https://foo:bar@example.org/'

or via token auth:

mo_url_auth_token: 'the token to use'

[smn]

@miltontony @KaitCrawford @jpaidoussi ready for review

[smn]

This is a backwards compatible change.

[mracter]

+1