Update cmd in readme

update option with "--tools=$PATH_TO_TOOLS"
Merge pull request #9 from tinazhao/master

Update cmd in readme
[demo-wrt] Add 8 TCs to demo express for wrt

- ManifestDemo3: xwalk-2737 Unexpected colour cast for .bmp format icons

Impacted TCs num(approved): New 8, Update 0, Delete 0
Unit test Platform: Android
Android test result summary: Pass 7, Fail 1, Block 0
Merge pull request #15 from wanghongjuan/wanghongjuan/wrt/android

[demo-wrt] Add 8 TCs to demo express for wrt