Add a tox.ini placeholder

This doesn't do much but allows the python-jobs to pass in gate
in the meantime.

Long term we can employ dib-lint from diskimage-builder to enforce
some lintian checks on the element code.

Change-Id: I14331c57b4cc7525af47c9d4b83ff6e879e1c549

tox.ini

@@ -0,0 +1,18 @@
+[tox]
+envlist = py34,py26,py27,pep8
+minversion = 1.6
+skipsdist = True
+
+[testenv]
+commands=
+    python -c "print 'nothing to do yet'"
+
+[testenv:pep8]
+commands =
+    python -c "print 'nothing to do yet'"
+
+[testenv:venv]
+commands = {posargs}
+
+[testenv:docs]
+commands = python setup.py build_sphinx