Delete '.gitlab-ci.yml'

This file obviously doesn't serve a purpose since we're not using Gitlab CI.

.gitlab-ci.yml

@@ -1,47 +0,0 @@
-# This file is a template, and might need editing before it works on your project.
-# Official framework image. Look for the different tagged releases at:
-# https://hub.docker.com/r/library/node/tags/
-image: node:12
-
-stages:
-  - lint
-  - build
-  - test
-  - deploy
-
-lint:
-  stage: lint
-  script:
-    - yarn
-    - npm run lint
-    - npm run stylelint
-
-test:
-  stage: test
-  variables:
-    APT_CACHE_DIR: apt-cache
-  script:
-    - mkdir -pv $APT_CACHE_DIR && apt-get -qq update
-    - apt install firefox-esr -y --no-install-recommends
-    - firefox --version
-    - yarn
-    - yarn unit
-
-build:
-  stage: build
-  script:
-    - yarn
-    - npm run build
-  artifacts:
-    paths:
-    - dist/
-
-docs-deploy:
-  stage: deploy
-  image: alpine:latest
-  only:
-  - develop@pleroma/pleroma-fe
-  before_script:
-  - apk add curl
-  script:
-  - curl -X POST -F"token=$DOCS_PIPELINE_TRIGGER" -F'ref=master' https://git.pleroma.social/api/v4/projects/673/trigger/pipeline