[maven-release-plugin] prepare release opentok-java-sdk-0.91.57
[maven-release-plugin] prepare release opentok-java-sdk-0.91.57

Kwasniewski/Opentok-Java-SDK,drahot/Opentok-Java-SDK,mukesh-kum/Opentok-Java-SDK,CamioCam/Opentok-Java-SDK,Kwasniewski/Opentok-Java-SDK,opentok/Opentok-Java-SDK,opentok/Opentok-Java-SDK,mukesh-kum/Opentok-Java-SDK,drahot/Opentok-Java-SDK,CamioCam/Opentok-Java-SDK