Adding Dockerfile with support files to build a minimal docker image running i2p.

Docker.expt

@@ -0,0 +1,7 @@
+#!/usr/bin/expect
+set timeout 15;
+spawn java -jar /tmp/i2pinstall.jar -console
+expect {
+ -re ".*press 1 to continue, 2 to quit, 3 to redisplay" {send "1\r"; exp_continue;}
+ -re "Select target path *" {send "/opt/i2p\r"; exp_continue;}
+}