fix the exchange option autoDelete default value to false in README.md

The default value of autoDelete option when creating an exchange is actually false. However, the document says it is true. Fix the document such that it matches the actual behavior.
Merge pull request #191 from tcpip106/patch-1

fix the exchange option autoDelete default value to false in README.md
Handled errors occurred in Connection and forced the object to emit the 'error' message such that the caller can handle when an error occurs.
Added the test.
Merge pull request #193 from shiroyuki/patch-1

Properly handle connection errors
Exchange.publish should not modify its arguments