`DockerCompose.exec()` that supports stdin

The pg_restore command can take a file argument, or you can pass the file contents over stdin. In order to pass a file, you have to deal with mounting, but over stdin you don't. Right now there's no way to pass content to stdin, and it would be useful if there was.

Maybe add an Optional<byte[]> stdin parameter which would be written to the process stdin?

docker-compose-rule/docker-compose-rule-core/src/main/java/com/palantir/docker/compose/execution/DockerComposeExecOption.java

Lines 23 to 26 in c789acc

    
           @Value.Immutable 
        
           public abstract class DockerComposeExecOption { 
        
               @Value.Parameter 
        
               public abstract List<String> options();

	@Value.Immutable
	public abstract class DockerComposeExecOption {
	@Value.Parameter
	public abstract List<String> options();