Add v1.5.4 to CHANGELOG.md
Add v1.5.4 to CHANGELOG.md
eunmin/Hystrix,mickdwyer/Hystrix,eunmin/Hystrix,mebigfatguy/Hystrix,mebigfatguy/Hystrix,wangsan/Hystrix,ianynchen/Hystrix,mattrjacobs/Hystrix,mickdwyer/Hystrix,justinjose28/Hystrix,Netflix/Hystrix,mattrjacobs/Hystrix,wangsan/Hystrix,justinjose28/Hystrix,wangsan/Hystrix,mebigfatguy/Hystrix,mattrjacobs/Hystrix,justinjose28/Hystrix,eunmin/Hystrix,mickdwyer/Hystrix