add Dockerfile for bedtools:2.25.0

src/nf_modules/BEDtools/2.25.0/Dockerfile

+FROM ubuntu:16.04
+MAINTAINER Laurent Modolo
+
+ENV BEDTOOLS_VERSION=2.25.0
+ENV PACKAGES bedtools=${BEDTOOLS_VERSION}*
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends ${PACKAGES} && \
+    apt-get clean

src/nf_modules/BEDtools/2.25.0/docker_init.sh

+#!/bin/sh
+docker build src/nf_modules/BEDtools/2.25.0 -t 'bedtools:2.25.0'