Remove braintree dependency, should no longer be needed to run tests

.github/workflows/tests.yml

@@ -42,7 +42,7 @@ jobs:
         sudo apt-get install -y libcurl4-openssl-dev libpython3-dev libssl-dev
         python -m pip install --upgrade pip
         pip install -r requirements.txt
-        pip install apprise braintree minio mysqlclient
+        pip install apprise minio mysqlclient
     - name: Run Tests
       env:
         DB: ${{ matrix.db }}