add build status to README
add build status to README

CptJason/elastic,nizsheanez/elastic,mruse/elastic,hustbill/elastic,TinLe/elastic,grafov/elastic,harrisonchen/elastic,dorsha/elastic,guilherme-santos/elastic,grafov/elastic,guilherme-santos/elastic,antonikonovalov/elastic,yonglehou/elastic,olivere/elastic,olivere/elastic,gmack/elastic,cep21/elastic