Prefer composer distribution downloads for travis build
Prefer composer distribution downloads for travis build

Speed up build time by preferring to download archives rather than
cloning repos when building on travis.

exlant/kohana,jellycheng/kohana,mattwadey/kohana,qianzy96/kohana,16nsk/kohana,gold3bear/kohana,driutheman/kohana,driutheman/kohana,yeysman/kohana,zhangjingpu/kohana,kohana/kohana,JanvanCasteren/kohana,web-player/kohana,dreamsxin/kohana,exlant/kohana,anhnt0212/kohana,ajose1024/kohana