tests/artifactcache: add __init__.py file to make it a package

tests/integration was lacking a __init__.py file, meaning it was not
recognized as a python package, and thus, pylint would not check
anything inside the directory.

Adding __init__.py ensures we have correct checks here.

1 files changed, 0 insertions, 0 deletions

diff --git a/tests/artifactcache/__init__.py b/tests/artifactcache/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/artifactcache/__init__.py