Attempt to add theia-docker-image build to pipeline

concourse/tasks/prepare-theia-docker-image.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+set -e
+workdir=$(pwd)
+cp -R ${workdir}/sts4/concourse/theia-docker-image/* ${workdir}/output
+for i in ${workdir}/*-vsix-*/*.vsix ; do
+    cp "$i" ${workdir}/output/plugins/
+done
+
+ls -Rl ${workdir}/output
+

concourse/tasks/prepare-theia-docker-image.yml

@@ -0,0 +1,15 @@
+platform: linux
+image_resource:
+  type: registry-image
+  source:
+    repository: kdvolder/sts4-build-env
+inputs:
+- name: sts4
+- name: s3-concourse-vsix-snapshot
+- name: s3-spring-boot-vsix-snapshot
+- name: s3-bosh-vsix-snapshot
+- name: s3-manifest-yaml-vsix-snapshot
+outputs:
+- name: output
+run:
+  path: sts4/tasks/prepare-theia-docker-image.sh