tests: add basic test

[daywalker90]

Hi, since the plugins repo will require plugins to have tests in the future, here is a very basic test.
setup.sh will build the binary during CI. tests/test_cln_ntfy.py contains the test and currently only checks if the plugins starts with the node and if the plugin options exist.

It would be nice to actually test a notification!

You can run tests like this:

Install dependencies:

pip3 install pyln-client pyln-testing

Build the plugin

cargo build

run tests :

pytest tests/test_cln_ntfy.py
# if you use a different profile than debug for compiling set the RUST_PROFILE like this:
RUST_PROFILE=release pytest tests/test_cln_ntfy.py

[daywalker90]

had to fix the setup.sh. It says i closed this PR but i did not do that oO