Add assets step

codeship-steps.yml

@@ -1,6 +1,9 @@
 # This is where we define the test steps that would be run in a Codeship Pro build.
 # The build passes as long as every test step returns with a non-zero exit code.
 # See here for more: https://documentation.codeship.com/pro/builds-and-configuration/steps/
+- name: build_assets
+  command: bin/codeship_assets
+  service: app
 - name: run_mix_test
   command: /bin/bash -c 'mix ecto.create && mix test'
   service: app