Improved tempest plugin sanity check script

* To use a fresh venv, use `--clear` option when creating a virtualenv
* Removes the project as the script fails to uninstall the dependencies.
* Added missing tempest plugins
* Log the stdout of each plugin in a file
* Adds some plugins to BLACKLIST to avoid errors

Change-Id: I5068d96105a22cbfd33f5900f4bdc21b47a65c06
2 files changed