- rework running of liveconfig tests

- better README reflecting how to use things, don't advertise
  run-integration-tests to only have one documented way
  and use less tools for rust-devs that just want to run
  python tests

- fix test skipping and get circle-ci to play along

- update docker related docs as well

run-integration-tests.sh

@@ -23,7 +23,7 @@ if [ $? != 0 ]; then
 fi
 
 pushd python
-if [ -e "./liveconfig" ]; then
+if [ -e "./liveconfig" && -z "$DCC_PY_LIVECONFIG" ]; then
     export DCC_PY_LIVECONFIG=liveconfig
 fi
 tox "$@"