Upgrade Docker Client to newer one

[Bartosz Firyn]

Hello @xebialabs team,

Overcast is using pretty old Docker Client which disallow use of Unix socket when communicating with Docker REST interface. The one currently used is 2.4.2 but I verified 2.7.6 to work perfectly well. By overriding this dependency with newer one I was able to spawn new containers without reconfiguring my Docker daemon to listen on TCP port. Also, with newer Docker Client my Overcast configuration utilizes unix:// socket protocol and working just fine without any additional changes in the Overcast code.

Example:

mysql {
    dockerHost="unix:///var/run/docker.sock"
    dockerImage="mysql:5.6"
    exposeAllPorts=true
    remove=true
    env=["MYSQL_ROOT_PASSWORD=foo","MYSQL_USER=root","MYSQL_DATABASE=bar"]
    command=["mysqld"]
}

Please consider upgrading to newer Docker Client.

[Ric Klaren]

Just upgraded to the latest.