Add autocolor for signs

1 job for master in 2 minutes and 2 seconds
Status Name Job ID Coverage
  Package
failed package_mcplugins #255
docker

00:02:02

 
Name Stage Failure
failed
package_mcplugins Package
# Compiler replay data is saved as:
# /builds/linus/mcplugins/replay_pid21.log
#
# If you would like to submit a bug report, please include
# instructions on how to reproduce the bug and visit:
# https://icedtea.classpath.org/bugzilla
#
/bin/bash: line 97: 21 Aborted (core dumped) mvn clean package
ERROR: Job failed: exit code 1