Merge pull request #6 from ChrisBoesch/master

Merge pull request #207 from ruijunhuang2010/master
Merge pull request #208 from ruijunhuang2010/master

Merge pull request #6 from ChrisBoesch/master
Merge pull request #7 from ChrisBoesch/master

update
Merge pull request #209 from ruijunhuang2010/master

Merge pull request #7 from ChrisBoesch/master
Merge pull request #211 from ShaikDawood/master

Update: Challenge message submission API
Merge pull request #76 from ChrisBoesch/master

Updates