Ensure dummy channels get a stasis topic.

Fixes test failure introduced in r382685.

(issue ASTERISK-20887)
(issue ASTERISK-20959)


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@382721 f38db490-d61c-443f-a65b-d21fe96a405b
Stasis documentation updates.

(issue ASTERISK-20887)
(issue ASTERISK-20959)



git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@382724 f38db490-d61c-443f-a65b-d21fe96a405b