Install and configure karma-junit-reporter

[stevehobbsdev]

Description

This PR installs and configures karma-junit-reporter for better test reporting.

Is there a need for this be optimised to only run on Circle?

Checklist

• I have added documentation for new/changed functionality in this PR or in auth0.com/docs
• All active GitHub checks for tests, formatting, and security are passing
• The correct base branch is being used, if not master

[lbalmaceda]

Is there a need for this be optimised to only run on Circle?

The --no-progress should be enough. The base test command is not changing, so I don't see anything additional we need to do. If we come across something we can figure out later.

Given we don't have it enabled yet (not public repo). Did you test this locally with the circleci CLI + docker?