Update Travis configuration

This will hopefully reduce the need for future en masse updates.

.travis.yml

@@ -1,11 +1,11 @@
 language: java
 jdk: oraclejdk8
 branches:
-  only: master
+  only:
+  - master
+  - "/.*-[0-9]+\\..*/"
 install: true
 script: ".travis/build.sh"
-after_success: ".travis/notify.sh Travis-Success"
-after_failure: ".travis/notify.sh Travis-Failure"
 env:
   global:
   - secure: N4AvtIOwZNgGYevVkFGzCQfSg4lpdKnWpnKEY6ko/ytVvFO+hxdlAkjqxE4kcy7MWBXx0yGkkc0gnvRqPeoUa17SuEUUt5MzpZB+GVVxWExI3oooh3XIqIfoUC2/xedYdsHrjgVRwrjsU/8okUbqjlWOrvxxN7ZGtPKhDYCPtj0=

.travis/build.sh

@@ -1,10 +1,3 @@
 #!/bin/sh
-dir="$(dirname "$0")"
-if [ "$TRAVIS_SECURE_ENV_VARS" = true \
-  -a "$TRAVIS_PULL_REQUEST" = false \
-  -a "$TRAVIS_BRANCH" = master ]
-then
-  mvn -Pdeploy-to-imagej deploy --settings "$dir/settings.xml"
-else
-  mvn install
-fi
+curl -fsLO https://raw.githubusercontent.com/scijava/scijava-scripts/master/travis-build.sh
+sh travis-build.sh