Remove test dependencies on python, JDK and zsh

[e2]

Summary

Aruba tests run "scripting tests", which require the above 3 system packages to be installed.

Expected Behavior

Aruba testing shouldn't require users to install Python, JDK and Zsh just to run tests locally.

Current Behavior

Aruba testing currently require users to install Python, JDK and Zsh.

Possible Solution

Use internal Aruba test scripts for better testing. If necessary, the could be in a special path (likefeatures/support/testscripts/bin) that should be prepended to $PATH so that shebangs like #/usr/bin/env example_app would work as the command was installed on the system (e.g. in /usr/bin or whatever).

This helps avoid issues like: #356 and helps reduce Docker overhead in local images for testing (#353).

Steps to Reproduce (for bugs)

1. Uninstall Python, JDK and Zsh
2. Run Aruba cucumber tests
3. Multiple scenarios fail

Context

Until my recent PR, script/boostrap didn't even detect the existence of python or javac. Also my personal Zsh broke tests - which obviously shouldn't ever happen.

Your Environment

• Version used: master
• Operating System and version: Linux