Pip is not required on osx

[rain-on]

scripts/acceptance.sh expects a number of core utils to be available on the system.

This includes "pip" (the python package manager).

On an OSX host, the pip package is installed as part of the python3 installation (via homebrew) - however no system-command is created to access it.

However, once inside a virtual-environment pip is available, as the module is wrapped by the <venv>/bin/pip script.