Which Stripe api key should be used for unit tests

A bit of context: I started implementing payment in my project using Stripe, and I started thinking about how to write the tests. After learning a bit about how it should be done and having into account the "don't mock what you don't own" philosophy, I decided to implement a wrapper for stripe API and I now have two kinds of tests: Tests for my application mocking the API wrapper, and tests for the API wrapper (which I don't run as often as the ones for my app). This second tests call stripe for real, so I need to provide a Stripe API Key. And here's where my question comes in.

Question: Should I use my account's test api key for unit testing, or can I use a generic Stripe API key? Being them unit tests, I don't want them to leave any persistent logs to my account, not even on the test dashboard.

Searching in google I found the following api key: tGN0bIwXnHdwOa85VABjPdSn8nWY7G7I and unlike the test api key from my account, it doesn't follow the pattern "pk_test_*", but it does work with stripe and returns correct responses. If you are wondering where did I get that key (and if I should be publishing it), it has been officially published by stripe in blog posts as well as repositories, but I couldn't find any explanation in the documentation or anywhere else, hence this question.