Refactor Docker Compose examples and plugins, add pytest tests

- Adjusted Compose files to build images locally instead of pulling.
- Simplified examples by removing `/etc/hosts` entry instructions.
- Enhanced `cloudflare.py` plugin with a configurable log format.
- Improved `generate-keys.sh` for portability using `$SCRIPT_DIR`.
- Added end-to-end tests for Compose examples using pytest.

examples/docker/docker-compose-multi-containers.yml

@@ -46,7 +46,10 @@
 
 services:
   haproxy:
-    image: byjg/easy-haproxy:5.0.0
+    build:
+      context: ../../
+      dockerfile: build/Dockerfile
+    image: byjg/easy-haproxy:local
     volumes:
       - /var/run/docker.sock:/var/run/docker.sock
     environment:
@@ -56,7 +59,8 @@ services:
       HAPROXY_PASSWORD: password
       HAPROXY_STATS_PORT: 1936
     ports:
-        - 19901:19901
+      - 19901:19901
+      - 1936:1936
 
 
   nginx: