Better travis ci config.
Better travis ci config.

Lifted from https://github.com/codahale/metrics/blob/ca79f9bf26bcc2a0dde8373c3a3fb81f6bf20818/.travis.yml

karl82/metrics-spring,jxqlovejava/metrics-spring,fgaule/metrics-spring,alex859/metrics-spring,wyzssw/metrics-spring,jongyoul/metrics-spring,ryantenney/metrics-spring,davidkarlsen/metrics-spring,segeon/metrics-spring