Update Travis configuration

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

Author: ctrueden

.travis.yml

@@ -1,6 +1,10 @@
 language: java
 jdk: oraclejdk8
 branches:
-  only: master
+  only:
+  - master
+  - "/.*-[0-9]+\\..*/"
 install: true
 script: ".travis/build.sh"
+env:
+  global:

.travis/build.sh

@@ -1,2 +1,3 @@
 #!/bin/sh
-mvn install
+curl -fsLO https://raw.githubusercontent.com/scijava/scijava-scripts/master/travis-build.sh
+sh travis-build.sh