Replace log.exception with debug, it spams log when slave is dead

[qadmium]

Without tests, cant build against latest tox image fails

`pypy-django18 create: /app/.tox/pypy-django18 ERROR: invocation failed (exit code 1), logfile: /app/.tox/pypy-django18/log/pypy-django18-0.log ERROR: actionid: pypy-django18 msg: getenv cmdargs: ['/.pyenv/versions/3.7.0/bin/python', '-m', 'virtualenv', '--python', '/.pyenv/shims/pypy', 'pypy-django18']

Using base prefix '/.pyenv/versions/pypy3.3-5.5-alpha' New pypy executable in /app/.tox/pypy-django18/bin/pypy Installing setuptools, pip, wheel... Complete output from command /app/.tox/pypy-django18/bin/pypy - setuptools pip wheel: DEPRECATION: Python 3.3 supported has been deprecated and support for it will be dropped in the future. Please upgrade your Python. Looking in links: /.pyenv/versions/3.7.0/lib/python3.7/site-packages, /.pyenv/versions/3.7.0/lib/python3.7/site-packages/virtualenv_support Collecting setuptools Using cached https://files.pythonhosted.org/packages/7f/e1/820d941153923aac1d49d7fc37e17b6e73bfbd2904959fffbad77900cf92/setuptools-39.2.0-py2.py3-none-any.whl Collecting pip Collecting wheel wheel requires Python '>=2.7, !=3.0., !=3.1., !=3.2., !=3.3.' but the running Python is 3.3.5

...Installing setuptools, pip, wheel...done. Traceback (most recent call last): File "/.pyenv/versions/3.7.0/lib/python3.7/site-packages/virtualenv.py", line 2343, in main() File "/.pyenv/versions/3.7.0/lib/python3.7/site-packages/virtualenv.py", line 712, in main symlink=options.symlink) File "/.pyenv/versions/3.7.0/lib/python3.7/site-packages/virtualenv.py", line 947, in create_environment download=download, File "/.pyenv/versions/3.7.0/lib/python3.7/site-packages/virtualenv.py", line 904, in install_wheel call_subprocess(cmd, show_stdout=False, extra_env=env, stdin=SCRIPT) File "/.pyenv/versions/3.7.0/lib/python3.7/site-packages/virtualenv.py", line 796, in call_subprocess % (cmd_desc, proc.returncode)) OSError: Command /app/.tox/pypy-django18/bin/pypy - setuptools pip wheel failed with error code 1 Running virtualenv with interpreter /.pyenv/shims/pypy

ERROR: Error creating virtualenv. Note that some special characters (e.g. ':' and unicode symbols) in paths are not supported by virtualenv. Error details: InvocationError('/.pyenv/versions/3.7.0/bin/python -m virtualenv --python /.pyenv/shims/pypy pypy-django18 (see /app/.tox/pypy-django18/log/pypy-django18-0.log)', 1)`