Add interval option into the home timeline Agent

ref: #37
Merge pull request #38 from ykzts/add-home_timeline-interval-option

Add interval option into the home timeline Agent
update dependency
use stub insted of stub!
Add description of a stream option into document
Search expanded URL from the URLs entities
Merge pull request #39 from ykzts/add-docs-stream-option

Add description of a stream option into document
Merge pull request #40 from ykzts/search-expanded-url-from-entities

Search expanded URL from the URLs entities
use double insted of mock
use double insted of stub
bump version to 0.4.2