chore: remove Travis file

.travis.yml

@@ -1,61 +0,0 @@
-os: 'linux'
-dist: 'focal'
-
-language: 'shell'
-
-services:
-  - 'docker'
-
-env:
-  - 'VERSION=latest'
-  - 'VERSION=5.4'
-  - 'VERSION=5.4-apache'
-  - 'VERSION=5.4-fpm'
-  - 'VERSION=5.5'
-  - 'VERSION=5.5-apache'
-  - 'VERSION=5.5-fpm'
-  - 'VERSION=5.6'
-  - 'VERSION=5.6-apache'
-  - 'VERSION=5.6-fpm'
-  - 'VERSION=7.0'
-  - 'VERSION=7.0-apache'
-  - 'VERSION=7.0-fpm'
-  - 'VERSION=7.1'
-  - 'VERSION=7.1-apache'
-  - 'VERSION=7.1-fpm'
-  - 'VERSION=7.2'
-  - 'VERSION=7.2-apache'
-  - 'VERSION=7.2-fpm'
-  - 'VERSION=7.3'
-  - 'VERSION=7.3-apache'
-  - 'VERSION=7.3-fpm'
-  - 'VERSION=7.4'
-  - 'VERSION=7.4-apache'
-  - 'VERSION=7.4-fpm'
-  - 'VERSION=8.0'
-  - 'VERSION=8.0-apache'
-  - 'VERSION=8.0-fpm'
-
-install:
-  - 'travis_wait 30 make build VERSION=${VERSION}'
-  - '[ "$NO_DEV" = "1" ] || make -C dev build VERSION=${VERSION}'
-
-script:
-  - 'make test VERSION=${VERSION}'
-  - '[ "$NO_DEV" = "1" ] || make -C dev test VERSION=${VERSION}'
-
-before_deploy:
-  - 'echo "$DOCKER_PASSWORD" | docker login -u "$DOCKER_USERNAME" --password-stdin'
-
-deploy:
-  - provider: 'script'
-    script: 'make push VERSION=${VERSION}'
-    on:
-      repo: 'chialab/docker-php'
-      branch: 'master'
-  - provider: 'script'
-    script: 'make -C dev push VERSION=${VERSION}'
-    on:
-      repo: 'chialab/docker-php'
-      branch: 'master'
-      condition: '"$NO_DEV" != "1"'