add docker files for pigz

src/nf_modules/pigz/2.4/Dockerfile

+FROM ubuntu:18.04
+MAINTAINER Laurent Modolo
+
+ENV PIGZ_VERSION=2.4
+ENV PACKAGES pigz=${PIGZ_VERSION}*
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends ${PACKAGES} && \
+    apt-get clean

src/nf_modules/pigz/2.4/docker_init.sh

+#!/bin/sh
+docker build src/nf_modules/pigz/2.4 -t 'pigz:2.4'