allow *.canvas.docker in the docker-compose dev environment

The leading dot is nginx syntax for allowing both `canvas.docker` and `*.canvas.docker`

Also pull in libxmlsec1-dev, for SAML.

Change-Id: I4281252053b7d890b08c06c30ad17f5b11670579
Reviewed-on: https://gerrit.instructure.com/52720
Tested-by: Jenkins
Reviewed-by: Tyler Pickett <tpickett@instructure.com>
Reviewed-by: Zach Wily <zach@instructure.com>
Product-Review: Brian Palmer <brianp@instructure.com>
QA-Review: Brian Palmer <brianp@instructure.com>

docker-compose.yml

@@ -34,7 +34,7 @@ web:
     - kinesis
   environment:
     RACK_ENV: development
-    VIRTUAL_HOST: canvas.docker
+    VIRTUAL_HOST: .canvas.docker
 
 jobs:
   build: ./docker-compose

docker-compose/Dockerfile

@@ -8,6 +8,7 @@ RUN  apt-get update -qq \
        locales \
        nodejs \
        postgresql-client \
+       libxmlsec1-dev \
   && rm -rf /var/lib/apt/lists/*
 
 # Ensure UTF-8 locale