Remove the ec2 api tests from tempest

With the introduction of tempest plugins we can now remove the third
party tests for the ec2 api using boto. They've always been the ugly
duckling in tempest (except that it never turned into a swan) where
they go against some of the fundamental principles of tempest tests.
For exaple, like having it's own client implementation, oh and testing
OpenStack APIs. This patch removes all the pieces of the third party
test dir and deprecates all the config options related to boto. A
plugin implementation is being worked [1] that can be used to fill
the coverage hole left by removing these from the tempest tree

[1] https://github.com/mtreinish/tempest_ec2

Change-Id: Ib5e24e19bcba9808a9f49fe7f328668df77fe4f9
diff --git a/README.rst b/README.rst
index 45cb4c0..71e185f 100644
--- a/README.rst
+++ b/README.rst
@@ -87,7 +87,7 @@
    be done with testr directly or any `testr`_ based test runner, like
    `ostestr`_. For example, from the working dir running::
 
-     $ ostestr --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.(api|scenario|thirdparty))'
+     $ ostestr --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.(api|scenario))'
 
    will run the same set of tests as the default gate jobs.