feat: automated integration test for example/basic

Adds automated CI integration tests to the basic example.
The integration tests launch and configure a keycloak server, launch the
example and test its functionality with a headless browser.

examples/basic/README.md

@@ -0,0 +1,22 @@
+This example is a basic web application to demonstrate the features of the `axum-oidc`-crate.
+It has three endpoints:
+- `/logout` - Logout of the current session using `OIDC RP-Initiated Logout`.
+- `/foo` - A handler that only can be accessed when logged in.
+- `/bar` - A handler that can be accessed logged out and logged in. It will greet the user with their name if they are logged in.
+
+# Running the Example
+## Dependencies
+You will need a running OpenID Connect capable issuer like [Keycloak](https://www.keycloak.org/getting-started/getting-started-docker) and a valid client for the issuer.
+
+You can take a look at the `tests/`-folder to see how the automated keycloak deployment for the integration tests work.
+
+## Setup Environment
+Create a `.env`-file that contains the following keys:
+```
+APP_URL=http://127.0.0.1:8080
+ISSUER=<your-issuer>
+CLIENT_ID=<your-client-id>
+CLIENT_SECRET=<your-client-secret>
+```
+## Run the application
+`RUST_LOG=debug cargo run`