From Lunar : change name to match python naming

[asmodehn]

This is because pyros structure has now changed to rely on namespace packages (from setuptools)

[asmodehn]

We dropped the idea of namespace package, at least while we are on python2.7
See pyros-dev/pyros-common#1.

Also the ROS package is not created so we are still free to name it what we want.
This should be pyros_interfaces_ros to match the intended structure.