Remove node_modules volume

We're removing this volume for now because it ends up getting the wrong
permissions making it impossible for a fresh install to work properly.

Change-Id: I9e08510722bf7bcc8b87c04fce697d5ba26f299b
Reviewed-on: https://gerrit.instructure.com/73495
Reviewed-by: Clay Diffrient <cdiffrient@instructure.com>
Tested-by: Jenkins
Product-Review: Tyler Pickett <tpickett@instructure.com>
QA-Review: Tyler Pickett <tpickett@instructure.com>

docker-compose.yml

@@ -38,7 +38,6 @@ web: &WEB
   build: ./docker-compose
   volumes:
     - "canvas-gems:/home/docker/.gem/ruby/2.1.0"
-    - "canvas-node_modules:/usr/src/app/node_modules"
     - ".:/usr/src/app"
   links:
     - consul