actions: add docker build (#317)

.github/workflows/build-docker.yml

+name: Docker Multi-Architecture Build
+
+on:
+  push:
+    paths-ignore:
+      - "**.md"
+    branches:
+      - master
+
+jobs:
+  build-docker:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+        with:
+          platforms: all
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: docker/setup-buildx-action@v1
+        with:
+          version: latest
+      - name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          file: ./Dockerfile
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: zedeus/nitter:latest,zedeus/nitter:${{ github.sha }}

.travis.yml

 jobs:
   include:
-    - stage: build
-      if: (NOT type IN (pull_request)) AND (branch = master)
-      language: minimal
-      services:
-        - docker
-      script:
-        - docker build -t $IMAGE_NAME:$TRAVIS_COMMIT .
-        - echo $DOCKERHUB_PASSWORD | docker login -u $DOCKERHUB_USERNAME --password-stdin
-        - docker push $IMAGE_NAME:$TRAVIS_COMMIT
-    - stage: deploy
-      if: (NOT type IN (pull_request)) AND (branch = master)
-      language: minimal
-      services:
-        - docker
-      script:
-        - docker pull $IMAGE_NAME:$TRAVIS_COMMIT
-        - docker tag $IMAGE_NAME:$TRAVIS_COMMIT $IMAGE_NAME:latest
-        - echo $DOCKERHUB_PASSWORD | docker login -u $DOCKERHUB_USERNAME --password-stdin
-        - docker push $IMAGE_NAME:latest
     - stage: test
       if: (NOT type IN (pull_request)) AND (branch = master)
       dist: bionic