add test suite. See #197

This test suite is implemented using [bats](https://github.com/sstephenson/bats).

Not all features are tested. For instance ssl features and custom nginx config are missing. Probably others.

This test suite won't work with TravisCI. Too many evenings were wasted trying to overcome [issues](http://stackoverflow.com/questions/32846800/travis-fails-to-stop-docker-containers) that arises only on the TravisCI platform. However it runs on [CircleCI](https://circleci.com) which is also free for opensource projects.

test/multiple-hosts.bats

@@ -0,0 +1,47 @@
+#!/usr/bin/env bats
+load test_helpers
+SUT_CONTAINER=bats-nginx-proxy-${TEST_FILE}
+
+function setup {
+	# make sure to stop any web container before each test so we don't
+	# have any unexpected contaiener running with VIRTUAL_HOST or VIRUTAL_PORT set
+	docker ps -q --filter "label=bats-type=web" | xargs -r docker stop >&2
+}
+
+
+@test "[$TEST_FILE] start a nginx-proxy container" {
+	run nginxproxy $SUT_CONTAINER -v /var/run/docker.sock:/tmp/docker.sock:ro
+	assert_success
+	docker_wait_for_log $SUT_CONTAINER 3 "Watching docker events"
+}
+
+@test "[$TEST_FILE] nginx-proxy forwards requests for 2 hosts" {
+	# WHEN a container runs a web server with VIRTUAL_HOST set for multiple hosts
+	docker_clean bats-multiple-hosts-1
+	run docker run -d \
+		--label bats-type="web" \
+		--name bats-multiple-hosts-1 \
+		-e VIRTUAL_HOST=multiple-hosts-1-A.bats,multiple-hosts-1-B.bats \
+		--expose 80 \
+		-w /data \
+		python:3 python -m http.server 80
+	assert_success
+	run retry 5 1s curl_container bats-multiple-hosts-1 / --head
+	assert_output -l 0 $'HTTP/1.0 200 OK\r'
+
+	# THEN querying the proxy without Host header → 503
+	run curl_container $SUT_CONTAINER / --head
+	assert_output -l 0 $'HTTP/1.1 503 Service Temporarily Unavailable\r'
+
+	# THEN querying the proxy with unknown Host header → 503
+	run curl_container $SUT_CONTAINER /data --header "Host: webFOO.bats" --head
+	assert_output -l 0 $'HTTP/1.1 503 Service Temporarily Unavailable\r'
+
+	# THEN
+	run curl_container $SUT_CONTAINER / --head --header 'Host: multiple-hosts-1-A.bats'
+	assert_output -l 0 $'HTTP/1.1 200 OK\r' || (echo $output; echo $status; false)
+
+	# THEN
+	run curl_container $SUT_CONTAINER / --head --header 'Host: multiple-hosts-1-B.bats'
+	assert_output -l 0 $'HTTP/1.1 200 OK\r'
+}