Documents typo fixes
Documents typo fixes

* Fixed url for get cluster list
* default_image_id typo fixes

Change-Id: I5c10fbdfed4d7aeedaa70d5ea06790342326ae90

esikachev/sahara-backup,citrix-openstack-build/sahara,zhangjunli177/sahara,rnirmal/savanna,redhat-openstack/sahara,ekasitk/sahara,zhujzhuo/Sahara,esikachev/scenario,tellesnobrega/storm_plugin,esikachev/scenario,ekasitk/sahara,xme1226/sahara,zhujzhuo/Sahara,henaras/sahara,ekasitk/sahara,bigfootproject/sahara,redhat-openstack/sahara,redhat-openstack/sahara,rnirmal/savanna,bigfootproject/sahara,openstack/sahara,bigfootproject/sahara,tellesnobrega/sahara,egafford/sahara,xme1226/sahara,openstack/sahara,keedio/sahara,esikachev/scenario,tellesnobrega/storm_plugin,esikachev/sahara-backup,tellesnobrega/storm_plugin,citrix-openstack-build/sahara,zhujzhuo/Sahara,esikachev/sahara-backup,matips/iosr-2015,matips/iosr-2015,mapr/sahara,xme1226/sahara,henaras/sahara,tellesnobrega/sahara,egafford/sahara,zhangjunli177/sahara,henaras/sahara,crobby/sahara,zhangjunli177/sahara,citrix-openstack-build/sahara,keedio/sahara,mapr/sahara,matips/iosr-2015,crobby/sahara,crobby/sahara,keedio/sahara,mapr/sahara