add Graphviz to cwltool* Docker containers (#849)

& fix wheel building

Author: mr-c

build-cwl-docker.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 set -e
 docker build --file=cwltool.Dockerfile --tag=commonworkflowlanguage/cwltool-module --target module .
 docker build --file=cwltool.Dockerfile --tag=commonworkflowlanguage/cwltool .

cwltool.Dockerfile

@@ -1,6 +1,6 @@
 FROM python:3.6-alpine as builder
 
-RUN apk add --no-cache git
+RUN apk add --no-cache git gcc python3-dev libxml2-dev libxslt-dev libc-dev linux-headers
 
 WORKDIR /cwltool
 COPY . .
@@ -12,13 +12,13 @@ RUN pip install --no-index --no-warn-script-location --root=/pythonroot/ /wheels
 FROM python:3.6-alpine as module
 LABEL maintainer [email protected]
 
-RUN apk add --no-cache docker nodejs
+RUN apk add --no-cache docker nodejs graphviz libxml2 libxslt
 COPY --from=builder /pythonroot/ /
 
 FROM python:3.6-alpine
 LABEL maintainer [email protected]
 
-RUN apk add --no-cache docker nodejs
+RUN apk add --no-cache docker nodejs graphviz libxml2 libxslt
 COPY --from=builder /pythonroot/ /
 COPY cwltool-in-docker.sh /cwltool-in-docker.sh