ca option and reporting errors no ECONNREFUSED

I added the ```ca``` options to provide an array with the CAs that
winston-logstash secure socket accept, so it is provided to node client
secure socket connection.

I also added a checking in socket ```error``` listener to report to
transport eventEmitter when socket received an error different from
ECONNREFUSED
Added test for ca option and error reporting

I added a test to check the ca option and the error reporting so, I
regenerated the certificates and keys and provided another to check
which provoke an error on the transport socket to check the implemented
error reporting.

I also added a shell script to regenerate the server key and certificate
Merge pull request #6 from ifraixedes/if-tls-client-subjectalname

Provided CA parameter to pass to the tls socket connection and socket error non ECONNREFUSED reporting