[15.0] Tweak docker version

Need docker-ce 20 instead of docker-ce 18 for building Odoo 15 on debian:bullseye

.travis.yml

@@ -19,5 +19,14 @@ script:
   - make VERSION=$VERSION build
   - make VERSION=$VERSION test
 
+# Need docker-ce 20 instead of docker-ce 18 for building Odoo 15 on debian:bullseye
+# https://docs.travis-ci.com/user/docker/#installing-a-newer-docker-version
+before_install:
+  - if [ "$VERSION" = "15.0" ] ; then curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add - ; fi
+  - if [ "$VERSION" = "15.0" ] ; then sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" ; fi
+  - if [ "$VERSION" = "15.0" ] ; then sudo apt-get update ; fi
+  - if [ "$VERSION" = "15.0" ] ; then sudo apt-get -y -o Dpkg::Options::="--force-confnew" install docker-ce ; fi
+  - docker --version
+
 after_success:
   - travis/publish.sh

HISTORY.rst

@@ -42,6 +42,7 @@ Unreleased
 **Build**
 
 * Add new version for Odoo 15.0
+* [15.0] Need docker-ce 20 instead of docker-ce 18 for building Odoo 15 on debian:bullseye
 
 **Documentation**