Fixed README.md. 
Fixed README.md. 

* Unescape underscore syntax.
* Fixed Errors sample (HTTP Header)
mitsuruog/node-easymock,mitsuruog/node-easymock,s-cradle/node-easymock,CyberAgent/node-easymock,yjkim0/node-easymock,s-cradle/node-easymock,yjkim0/node-easymock,CyberAgent/node-easymock