Update Travis configuration

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

.travis.yml

 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: NqQnD838jkrZYdEdVBigS1nKaYDwf1u9mWidxenU+wE2/PLSYz8yO/mD9XTy1uaAji6yazNN/odQinIukcUr0rAGcFoxZg93GiXLGuLBosgUKx9OHm2IThOimhPoUjeoR2BcqA/EV7bordLTNHnM5ZCg4uQkasIIDZFZk7lPx9w=

.travis/build.sh

 #!/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

.travis/notify.sh

-#!/bin/sh
-curl -fs "https://jenkins.imagej.net/job/$1/buildWithParameters?token=$TOKEN_NAME&repo=$TRAVIS_REPO_SLUG&commit=$TRAVIS_COMMIT&pr=$TRAVIS_PULL_REQUEST"