Updating docker2singularity to use version 3.4.2

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.12.7-alpine3.10 as base
+FROM golang:1.13-alpine3.10 as base
 
 ################################################################################
 #
@@ -34,7 +34,7 @@ RUN apk add --no-cache linux-headers build-base openssl-dev util-linux util-linu
 RUN mkdir -p /usr/local/var/singularity/mnt && \
     mkdir -p $GOPATH/src/github.com/sylabs && \
     cd $GOPATH/src/github.com/sylabs && \
-    wget -qO- https://github.com/sylabs/singularity/releases/download/v3.4.1/singularity-3.4.1.tar.gz | \
+    wget -qO- https://github.com/sylabs/singularity/releases/download/v3.4.2/singularity-3.4.2.tar.gz | \
     tar xzv && \
     cd singularity && \
     ./mconfig -p /usr/local/singularity && \

README.md

@@ -5,12 +5,13 @@
 [![CircleCI](https://circleci.com/gh/singularityhub/docker2singularity.svg?style=svg)](https://circleci.com/gh/singularityhub/docker2singularity)
 
 Are you developing Docker images and you would like to run them on an HPC cluster 
-supporting [Singularity](https://www.sylabs.io/guides/2.5.1/user-guide/introduction.html)? 
+supporting [Singularity](https://www.sylabs.io/guides/latest/user-guide/)? 
 Are you working on Mac or Windows with no easy access to a Linux machine? If the pull, 
-build, and general commands to [work with docker images provided by Singularity](https://www.sylabs.io/guides/2.5.1/user-guide/singularity_and_docker.html?highlight=docker) natively do not fit your needs, 
-`docker2singularity` is an alternative way to generate Singularity images. 
+build, and general commands to work with docker images provided by Singularity
+natively do not fit your needs, `docker2singularity` is an alternative way to generate Singularity images. 
 This particular branch is intended for Singularity 2.5.1, which gives you a selection of image formats to build.
-The containers are also available for you on [Docker Hub](https://hub.docker.com/r/singularityware/docker2singularity/).
+The containers are available to you on [quay.io](https://quay.io/repository/singularity/docker2singularity), a
+nd older versions also available for you on [Docker Hub](https://hub.docker.com/r/singularityware/docker2singularity/).
 
 ## Usage
 
@@ -63,7 +64,8 @@ The last argument (without a letter) is the name of the docker image, as you wou
 
 If you want a legacy version, see the following other branches:
 
- - [v3.4.0](https://github.com/singularityhub/docker2singularity/tree/v3.3.0): Version 3.4.0 of Singularity.
+ - [v3.4.1](https://github.com/singularityhub/docker2singularity/tree/v3.4.1): Version 3.4.1 of Singularity.
+ - [v3.4.0](https://github.com/singularityhub/docker2singularity/tree/v3.4.0): Version 3.4.0 of Singularity.
  - [v3.3.0](https://github.com/singularityhub/docker2singularity/tree/v3.3.0): Version 3.3.0 of Singularity.
  - [v3.2.1](https://github.com/singularityhub/docker2singularity/tree/v3.2.1): Version 3.2.1 of Singularity.
  - [v3.1](https://github.com/singularityhub/docker2singularity/tree/v3.1): Version 3.1 of Singularity.

VERSION

@@ -1 +1 @@
-3.4.1
+3.4.2