Convenient shell things when logging in as impress user in production

Now, if I run `sudo -i -u impress` on the production server, it opens a
login bash shell, with all of the app's environment variables exported,
straight to `/srv/impress`.

This will let me quickly `cd current; bin/rails console` to start poking
at whatever needs poked!

deploy/setup.yml

@@ -98,7 +98,9 @@
       user:
         name: impress
         comment: Impress App
+        home: /srv/impress
         create_home: false
+        shell: /bin/bash
 
     - name: Create "impress-deployers" group
       group:
@@ -172,6 +174,18 @@
         mode: "755"
         state: directory
 
+    - name: Add a convenient .bash_profile for when we log in as "impress"
+      copy:
+        owner: impress
+        group: impress
+        dest: /srv/impress/.bash_profile
+        content: |
+          set -a # Export all of the below
+          RAILS_ENV=production
+          EXECJS_RUNTIME=Disabled
+          source /srv/impress/shared/production.env
+          set +a
+
     - name: Create the app's "versions" folder
       become_user: impress
       file: