💚 Minor tweaks to CI

* Only upload coverage on successful builds
* When a build fails, show the mosquitto logs

.travis.yml

@@ -30,12 +30,13 @@ before_cache:
 before_install:
   - if [[ -d $HOME/docker ]]; then ls $HOME/docker/*.tar.gz | xargs -I {file} sh -c "zcat {file} | docker load"; fi
   - docker pull eclipse-mosquitto:1.6.2
-  - docker run -d -p 127.0.0.1:1883:1883 eclipse-mosquitto:1.6.2
+  - docker run -d --name broker -p 127.0.0.1:1883:1883 eclipse-mosquitto:1.6.2 -- mosquitto -v
   - docker ps
   - go mod download
 install: go build ./...
 script: go test -race -v -coverprofile=profile.cov $(go list ./...)
-after_script:
+after_success:
   - go get github.com/mattn/goveralls
   - $GOPATH/bin/goveralls -coverprofile=profile.cov -service=travis-ci
-
+after_failure:
+  - docker logs broker