More Docker work

- Dockerfile now builds Inbucket inside the container
- Add starter inbucket.conf for Docker
- Add install.sh to build inbucket inside container
- Add customized greeting.html for Docker

etc/docker/install.sh

@@ -0,0 +1,33 @@
+#!/bin/sh
+# install.sh
+# description: Build, test, and install Inbucket. Should be executed inside a Docker container.
+
+# Note: we assume there are no spaces in dir paths
+installdir=${INBUCKET_HOME}
+srcdir=${INBUCKET_SRC}
+bindir=$installdir/bin
+
+# Setup
+export GOBIN=$bindir
+builddate="$(date --iso-8601=seconds)"
+set -e
+cd $srcdir
+go clean
+
+# Build
+echo "### Fetching Dependencies"
+go get -d -v ./...
+go get -v github.com/stretchr/testify
+
+echo "### Testing Inbucket"
+go test ./...
+
+echo "### Building Inbucket"
+mkdir -p $bindir
+go build -o inbucket -race -ldflags "-X main.BUILD_DATE '$builddate'" -v .
+
+echo "### Installing Inbucket"
+mv inbucket $bindir
+install etc/docker/inbucket.conf /etc/opt/inbucket.conf
+install etc/docker/greeting.html /etc/opt/inbucket-greeting.html
+cp -r themes $installdir/