Add a section to the README.rst that covers the process to add
bug signatures to elastic-recheck.
Change-Id: I93c830d8d2f414f5f52ae907e2a38a2a681c7534
Closes-bug: 1172387
Make repo support 'tox -epep8' as we want this to be the first gating
check.
Don't make any actual code changes, just change setup and add files.
Further work is needed to re-organize the code, but that can be in a
separate patch.