Migrate CI from Travis to GitHub Workflows

.github/workflows/ci.yml

@@ -0,0 +1,67 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: "0 12 * * 0"
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    continue-on-error: true
+
+    strategy:
+      fail-fast: false
+      matrix:
+        gtk_version: [2, 3]
+        include:
+          - gimp_git_tag: 'GIMP_2_10_22'
+            gtk_version: ''
+
+    container:
+      image: photoflow/docker-centos7-gimp
+      env:
+        GTK_VERSION: ${{ matrix.gtk_version }}
+        GIMP_GIT_TAG: ${{ matrix.gimp_git_tag }}
+        BABL_GIT_TAG: 'BABL_0_1_82'
+        GEGL_GIT_TAG: 'GEGL_0_4_26'
+
+    steps:
+      - name: checkout repository
+        uses: actions/checkout@v2
+
+      - name: build AppImage
+        run: |
+          ln -s "$PWD" /sources
+          exec /sources/mkappimage.sh
+
+      - name: archive built artifacts
+        uses: actions/upload-artifact@v2
+        with:
+          name: gimp-appimage
+          path: out/*
+          retention-days: 7
+
+  upload:
+    if: ${{ (github.event_name == 'push' && github.ref == 'refs/heads/master') || github.event_name == 'schedule' }}
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - name: retrieve artifacts
+        uses: actions/download-artifact@v2
+        with:
+          name: gimp-appimage
+          path: out/
+
+      - name: dump files
+        run:  ls -lh out/
+
+      - name: retrieve upload tool
+        run: wget -c https://github.com/aferrero2707/uploadtool/raw/master/upload_rotate.sh
+
+      - name: upload built files
+        run: bash ./upload_rotate.sh "continuous" out/*
+        env:
+          TRAVIS_REPO_SLUG: ${{ github.repository }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

README.md

@@ -1,4 +1,4 @@
-[![Build Status](https://travis-ci.org/aferrero2707/gimp-appimage.svg?branch=master)](https://travis-ci.org/aferrero2707/gimp-appimage)
+[![Build Status](https://github.com/aferrero2707/gimp-appimage/actions/workflows/ci.yml/badge.svg)](https://github.com/aferrero2707/gimp-appimage/actions/workflows/ci.yml)
 
 # Introduction