Fixed broken links in README

Change-Id: I4dacbb99ddc4a21693b6564101c8d8d9a263f0ad

Updated challenge documentation

Change-Id: Iad859dfe0c288ed1c2d0e42245bf6f9c70ea568f

Updated Changelog

Change-Id: Ia148688cf25a040807d0d51a085877f6d8334a75

Merge pull request carla-simulator#7 from SubhashiniPerumal/scenario

Implementation of Traffic Scenario 01