Implement application default credentials (#32)

diff --git a/tests/data/authorized_user.json b/tests/data/authorized_user.json
new file mode 100644
index 0000000..4787ace
--- /dev/null
+++ b/tests/data/authorized_user.json
@@ -0,0 +1,6 @@
+{
+  "client_id": "123",
+  "client_secret": "secret",
+  "refresh_token": "alabalaportocala",
+  "type": "authorized_user"
+}
diff --git a/tests/data/cloud_sdk.cfg b/tests/data/cloud_sdk.cfg
new file mode 100644
index 0000000..089aac5
--- /dev/null
+++ b/tests/data/cloud_sdk.cfg
@@ -0,0 +1,2 @@
+[core]
+project = example-project