Two Docker layers with files

This is a feature inspired by jib.
The plugin now copies dependencies first, and then the application JAR. It means that if there is just change in the application code, the layer with dependencies remains the same, so it hasn't to be pushed, and also hasn't to be downloaded in runtime environment. So it saves both space and bandwidth.

AdoptOpenJDK base images instead of OpenJDK

Also Gradle updated from 5.4.1 to 5.6.4.

OSType parsing fixed

1.8.2

fix docker info OSType parsing

stdout of Docker commands not swallowed if not required

1.8.1

stdout not swallowed if not required

Default Docker images updated and Gradle 5.4.1

1.8.0

Docker images updated

Default Docker images updated and Gradle 5.1.1

1.7.0

default images updated

Settings to copy files to Docker working directory

It's array of Files named filesToCopy. #7

Default Docker images updated

1.6.5

newer default images

Docker configuration directory removed correctly

1.6.4

Docker configuration directory removed correctly

Build arguments for custom Dockerfile

1.6.3

build arguments for custom Dockerfile