Log Message:
Update ruby-eventmachine to 1.2.5.

## 1.2.5 (July 27, 2017)
* Java: Use long for larger values in oneshot timer intervals [#784, #794]

## 1.2.4 (July 27, 2017)
* Java: Add EM_PROTO_SSL/TLS definitions [#773, #791]
* Fix IPv6 UDP get_peername [#788]
* Allow for larger values in oneshot timer intervals [#784, #793]
* Update extconf.rb to allow MinGW builds with OpenSSL 1.1.0 [#785]