RelValMC further clean up

RelValMC workload was removed in #4687, this patch cleans up remaining
relevant, now unnecessary, references.
Merge pull request #4691 from zdenekmaxa/relvalmc-removal-further-cleanup

RelValMC further clean up
ReqMgr TaskChain request templates added.

4 extra request templates for TaskChain workflows.
Fixes #4545
Merge pull request #4693 from zdenekmaxa/reqmgr-taskchain-testing-templates-4545

ReqMgr TaskChain request templates added.
SimpleMyProxy: use logger from arguments if there is one
Merge pull request #4694 from mmascher/simple-myproxy-logger

SimpleMyProxy: use logger from arguments if there is one
Trying to silence jenkins

Ticket #4695 complains about it, but a bunch of tests depend on
cmssw.cvs.cern.ch, which is flaking out a lot and killing tests.
I'm silencing jenkins to get rid of so many false negatives
Continuing to silence jenkins
ReqMgr2 unittests

-unittests framework for WMCore.REST based application
-first unittest for ReqMgr2 example REST API

@ticoann please review, I have eventually made some clean up and reshuffling.
Merge pull request #4697 from zdenekmaxa/reqmgr2-unittest-for-newrestapi

ReqMgr2 unittests