Reset retries connect and emit error when silent mode

I added the 'connect' event listener to socket to reset the connection
retries counter and 'error' emit to the transport when the maximum
connect retries is reached and the transport is 'silent' mode
Added test for 'error' emit when it swaps to silent

I added a test to check that transport emit an 'error' message when it
reaches the maximum connection retries and it swaps to ```silent``` mode
Merge pull request #8 from ifraixedes/if-emit-error-max-conn-reties-reached

If emit error when max connections reties has been reached