[FAB-2848] Remove orderer-n-kafka-n environment

Too early for this, should never have let it in to begin with. See [1].

Also note that a recent commit broke this environment entirely, since it
gave the `orderer` service a hard-coded `container-name`.

[1] http://hans.gerwitz.com/2004/08/12/premature-optimization-is-the-root-of-all-evil.html

Change-Id: Id496b707f2b2adbbc851fdc9f66c9da20f31641a
Signed-off-by: Kostas Christidis <kostas@christidis.io>

Author: Kostas Christidis