Add .gitlab-ci.yml and badges to README

.gitlab-ci.yml

@@ -0,0 +1,38 @@
+image: docker:stable
+
+stages:
+- build
+- push
+
+default:
+  before_script:
+  - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+
+build:
+  stage: build
+  script:
+  - docker pull $CI_REGISTRY_IMAGE:latest || true
+  - docker build --pull --cache-from $CI_REGISTRY_IMAGE:latest --tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA .
+  - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
+
+push latest:
+  stage: push
+  only:
+  - master
+  variables:
+    GIT_STRATEGY: none
+  script:
+  - docker pull $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
+  - docker tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA $CI_REGISTRY_IMAGE:latest
+  - docker push $CI_REGISTRY_IMAGE:latest
+
+push tag:
+  stage: push
+  variables:
+    GIT_STRATEGY: none
+  only:
+  - tags
+  script:
+  - docker pull $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
+  - docker tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_NAME
+  - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_NAME

README.md

@@ -1,4 +1,10 @@
 # mautrix-telegram
+![Languages](https://img.shields.io/github/languages/top/tulir/mautrix-telegram.svg)
+[![License](https://img.shields.io/github/license/tulir/mautrix-telegram.svg)](LICENSE)
+[![Release](https://img.shields.io/github/release/tulir/mautrix-telegram/all.svg)](https://github.com/tulir/mautrix-telegram/releases)
+[![GitLab CI](https://mau.dev/tulir/mautrix-telegram/badges/master/pipeline.svg)](https://mau.dev/tulir/mautrix-telegram/container_registry)
+[![Maintainability](https://img.shields.io/codeclimate/maintainability/tulir/mautrix-telegram.svg)](https://codeclimate.com/github/tulir/mautrix-telegram)
+
 A Matrix-Telegram hybrid puppeting/relaybot bridge.
 
 ### [Wiki](https://github.com/tulir/mautrix-telegram/wiki)