Add tests for nginx.conf directives (#1)

Adds tests to make sure all the `nginx.conf` directives (the redirects and rewrites and such) are all correct.

- Uses the `busted` framework
- The tests are run in a Docker container by the bash script `test.sh`
- Self-signed certs are generated in `Dockerfile` for all the domain names
- Adds new `Makefile` commands: `test`, `image-build` and `image-rm`

Reviewed-on: #1
Co-authored-by: Catalin Mititiuc <webdevcat@proton.me>
Co-committed-by: Catalin Mititiuc <webdevcat@proton.me>

app.ini

@@ -21,12 +21,13 @@ ROOT = /var/lib/gitea/data/gitea-repositories
 
 [server]
 ; SSH_DOMAIN = localhost
-SSH_DOMAIN = git.miti.sh
 ; DOMAIN = localhost
 DOMAIN = git.miti.sh
-HTTP_PORT = 3000
-; ROOT_URL = http://localhost:3000/
-ROOT_URL = https://git.miti.sh
+; HTTP_PORT = 3000
+PROTOCOL = unix
+ROOT_URL = https://git.miti.sh/
+HTTP_ADDR = /run/gitea/gitea.socket
+LOCAL_ROOT_URL =
 APP_DATA_PATH = /var/lib/gitea/data
 DISABLE_SSH = false
 SSH_PORT = 22