Add Docker support (to be used with development repo)

Author: Brian Sadler

Dockerfile

@@ -0,0 +1,20 @@
+# We currently use Ruby 1.9.3 in prod, but bundle install is failing with that in dev.
+# We also can't use the newest ruby because it broke support for the syck gem in v2.2.
+FROM ruby:2.1
+RUN apt-get update -qq && apt-get install -y build-essential libpq-dev
+
+# The rubycas Gemfile / gemspec doesn't specify a rails version since we use Apache Passenger modrails to run it in prod.  
+# Need this installed in the container to run the dev version.
+#RUN gem install rails -v 3.2
+
+RUN mkdir /app
+WORKDIR /app
+ADD Gemfile /app/Gemfile
+ADD rubycas-server.gemspec /app/rubycas-server.gemspec
+RUN bundle install
+
+# Do this after bundle install b/c if we do it before then changing any files 
+# causes bundle install to be invalidated and run again on the next build
+ADD . /app
+
+