*: Drop Jenkins

Since 199f2e07 (openshift/install e2e-aws add run smoke tests,
2018-08-28, openshift/release#1317) we've been running the smoke tests
on AWS via Prow, so we can drop our Jenkins bindings.  This commit
also drops Dockerfiles for some images which have been supplanted in
Prow by 5e94276 (add Dockerfiles for ci, 2018-09-06, openshift#223).

Author: wking

Jenkinsfile

@@ -51,11 +51,6 @@ In addition to our basic set of tests we have smoke tests which are running on A
   3. Get the approval of another person.
   4. Merge the PR.
 
-## Nightly Runs
-
-We use Jenkins to run our tests and our `nightly` builds against the master branch.
-Those jobs are executing smoke tests and building docker images.
-
 ## Running smoke tests locally
 
 ### 1. Expose environment variables