Replace Vagrant with Docker

tools/composer

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+source .env
+
+mkdir -p ./.composer/cache
+
+docker run \
+    --rm \
+    --interactive \
+    --tty \
+    --user $UID:$(id -g) \
+    --volume /etc/passwd:/etc/passwd:ro \
+    --volume /etc/group:/etc/group:ro \
+    --volume $PWD:/srv/homepage \
+    --volume $PWD/.composer:/tmp/.composer \
+    --env COMPOSER_HOME=/tmp/.composer \
+    ${HOMEPAGE_IMAGE} composer "$@"