Rewrite docker/dev.sh

Uses workers container rather than web for migrations, since web is
defined to have an entrypoint which shockingly RUNS THE WEB SERVER.
Sometimes my brilliance astounds me.

Also improves the setup by pulling needed images and not rebuilding the
core image when we only really need the "overlay" (od1-dev) image.

docker/dev.sh

@@ -4,15 +4,23 @@
 # set up.  Some things may need to be tweaked, such as only migrating once.
 # Feel free to copy this to create your own docker-compose adventure!
 
-# Stop everything
-docker-compose stop
+# Stop and clean up everything
+docker-compose down
 
-# Build, migrate, and clean up
-docker build --rm -t oregondigital/od1 -f docker/Dockerfile-dev .
-docker-compose run web bundle exec rake db:migrate
-docker-compose rm -f web
-docker-compose rm -f workers
-docker-compose rm -f resquehead
+# Pull images from dockerhub; nothing happens if you already have these
+docker pull oregondigital/od1
+docker pull oregondigital/solr
+docker pull oregondigital/phantomjs:1.8.1
+docker pull oregondigital/hydra-jetty:3.8.1-4.0
 
-# Restart
-docker-compose up
+# Rebuild the od1 dev container in case of code changes
+docker-compose build web
+
+# Run migrations
+docker-compose run workers bundle exec rake db:migrate
+
+# Restart in the background
+docker-compose up -d
+
+# Follow the web logs
+docker-compose logs -f web